From rfid-bounces@lists.ietf.org Mon May 09 17:57:24 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DVGFg-00076y-Ro; Mon, 09 May 2005 17:57:24 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DVGFg-00076t-0y for rfid@megatron.ietf.org; Mon, 09 May 2005 17:57:24 -0400 Received: from mx.sj.symbol.com (mx.sj.symbol.com [65.115.69.195]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id RAA16051 for ; Mon, 9 May 2005 17:57:20 -0400 (EDT) Received: from gwianameserver.sj.symbol.com (gwianameserver.sj.symbol.com [157.235.95.252]) by mx.sj.symbol.com (8.12.10/8.12.10) with ESMTP id j49LjhDq012760 for ; Mon, 9 May 2005 14:45:43 -0700 Received: from SJ-DOM-MTA by gwianameserver.sj.symbol.com with Novell_GroupWise; Mon, 09 May 2005 14:56:46 -0700 Message-Id: X-Mailer: Novell GroupWise Internet Agent 6.0.4 Date: Mon, 09 May 2005 14:56:35 -0700 From: "Clint Chaplin" To: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Cc: Subject: [Rfid] Test X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org ping _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid From rfid-bounces@lists.ietf.org Tue May 24 19:45:31 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Daj5W-0002SR-Tw; Tue, 24 May 2005 19:45:30 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Daj5V-0002SJ-2W for rfid@megatron.ietf.org; Tue, 24 May 2005 19:45:29 -0400 Received: from mail.intelleflex.com (mail.intelleflex.com [66.236.103.101]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id TAA06540 for ; Tue, 24 May 2005 19:45:25 -0400 (EDT) Received: from SureshLaptopIF (SureshLaptopIF.intelleflex.com [10.1.7.247]) by mail.intelleflex.com (8.13.1/8.13.1) with ESMTP id j4ONbBqR008971 for ; Tue, 24 May 2005 16:37:11 -0700 Message-Id: <200505242337.j4ONbBqR008971@mail.intelleflex.com> From: "Suresh Bhaskaran" To: Date: Tue, 24 May 2005 16:45:05 -0700 MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook, Build 11.0.6353 Thread-Index: AcVgupwml+OnLiRqQdK8V4+vhiR/aw== X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-DCC-CollegeOfNewCaledonia-Metrics: mail 1189; Body=1 Fuz1=1 Fuz2=1 X-Scanned-By: MIMEDefang 2.48 on 10.1.7.25 Cc: Subject: [Rfid] SLRRP-related questions X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============2027932524==" Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org This is a multi-part message in MIME format. --===============2027932524== Content-Type: multipart/alternative; boundary="----=_NextPart_000_0099_01C5607F.F00C7AF0" This is a multi-part message in MIME format. ------=_NextPart_000_0099_01C5607F.F00C7AF0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Krishna, et. al: Here are some questions I collected up relating to SLRRP: 1. How do you set server IP address and port (into reader) if reader initiates connection?! a. (telnet is one way; web server is another?!) 2. What comes back as message sequence number if you have multiple packet responses per command? a. E.g. Inventory Access Report 3. Reader Status report comes asynchronously. What is it's sequence number? a. (could set to 0) 4. What if Reader Status report comes asynchronously? What happens? 5. What happens if Stop Inventory, and there is partial data to be returned?! 6. Why does Access cmd and Inventory Cmd have both Antenna ID's? Does the Inventory Antenna override the Access Antenna?! 7. What if a stop Access is given in the middle of an Inventory cmd? What happens? Do the Access parameters "go away" in the middle of an inventory? 8. How do you know how many Inventory Access reports are coming (suppose a large report is fragmented into smaller pieces)? Thanks in advance. Suresh ------=_NextPart_000_0099_01C5607F.F00C7AF0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Krishna, et. = al:

 

Here are some questions I collected up relating to = SLRRP:

 

 

 

  1. How do = you set server IP address and port (into reader) if reader initiates = connection?!
    1. (telnet = is one way; web server is another?!)
  2. What = comes back as message sequence number if you have multiple packet responses per command? =
    1. E.g. = Inventory Access Report
  3. Reader = Status report comes asynchronously.  What is it’s sequence number? =
    1. (could = set to 0)
  4. What if = Reader Status report comes asynchronously?  What happens? =
  5. What = happens if Stop Inventory, and there is partial data to be returned?! =
  6. Why does = Access cmd and Inventory Cmd have both Antenna ID’s?  Does the = Inventory Antenna override the Access Antenna?! =
  7. What if a = stop Access is given in the middle of an Inventory cmd?  What happens?  Do the Access parameters “go away” in = the middle of an inventory?
  8. How do = you know how many Inventory Access reports are coming (suppose a large report is fragmented into smaller pieces)?

 

Thanks in advance.

 

Suresh

 

 

------=_NextPart_000_0099_01C5607F.F00C7AF0-- --===============2027932524== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid --===============2027932524==-- From rfid-bounces@lists.ietf.org Tue May 24 20:27:51 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DajkU-000131-VE; Tue, 24 May 2005 20:27:50 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DajkU-00012r-7M for rfid@megatron.ietf.org; Tue, 24 May 2005 20:27:50 -0400 Received: from mail.intelleflex.com (mail.intelleflex.com [66.236.103.101]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id UAA09242 for ; Tue, 24 May 2005 20:27:48 -0400 (EDT) Received: from SureshLaptopIF (SureshLaptopIF.intelleflex.com [10.1.7.247]) by mail.intelleflex.com (8.13.1/8.13.1) with ESMTP id j4P0JXg0009393 for ; Tue, 24 May 2005 17:19:33 -0700 Message-Id: <200505250019.j4P0JXg0009393@mail.intelleflex.com> From: "Suresh Bhaskaran" To: Date: Tue, 24 May 2005 17:27:26 -0700 MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook, Build 11.0.6353 Thread-Index: AcVgwIbnqvENbEI4Sl2BxjA+/gpPtw== X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-DCC-CollegeOfNewCaledonia-Metrics: mail 1189; Body=1 Fuz1=1 Fuz2=1 X-Scanned-By: MIMEDefang 2.48 on 10.1.7.25 Cc: Subject: [Rfid] Reader Discovery X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============2093383971==" Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org This is a multi-part message in MIME format. --===============2093383971== Content-Type: multipart/alternative; boundary="----=_NextPart_000_00A6_01C56085.DAE5B050" This is a multi-part message in MIME format. ------=_NextPart_000_00A6_01C56085.DAE5B050 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit One more SLRRP question: What are some simple easy ways (in the "Lightweight" spirit of SLRRP) to do discovery of the reader device? Some options/ideas that seem to have cropped up in various discussions: 1. UDP broadcast 2. DHCP server can give both IP address *and* server address to reader 3. Cisco-type discovery was mentioned as a possibility - I'm not too familiar with this. Is there some document/link that explains this and other options? At this stage, I'm not thinking of any "massively" scalable method for a large number. Simply, if one (or a few) readers come up, what are some ways they can get their IP addresses, and find out who their server is, and start talking to each other? Then the server can send a SLRRP command to get the reader capabilities. I noticed that there was not a whole lot about this in either the RP, or RM or ALE documents of the EPC global either. (I did a search on the word "discover", and didn't find any simple answers relating to the above questions). I know this could be a huge topic, but I just wanted some simple ideas/pointers here. Some documents/links discussing the overall concept would be great as well. Suresh ------=_NextPart_000_00A6_01C56085.DAE5B050 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

One more SLRRP question:

 

What are some simple easy ways (in the = “Lightweight” spirit of SLRRP) to do discovery of the reader = device?

 

Some options/ideas that seem to have cropped up in = various discussions:

 

  1. UDP = broadcast
  2. DHCP server can give = both IP address *and* server = address to reader
  3. Cisco-type discovery = was mentioned as a possibility – I’m not too familiar with = this…  Is there some document/link that explains this and other = options?

 

At this stage, I’m not thinking of any = “massively” scalable method for a large number.  Simply, if one (or a few) = readers come up, what are some ways they can get their IP addresses, and find out who = their server is, and start talking to each other?  Then the server can = send a SLRRP command to get the reader capabilities.

 

I noticed that there was not a whole lot about this = in either the RP, or RM or ALE documents of the EPC global either. (I did a = search on the word “discover”, and didn’t find any simple = answers relating to the above questions).

 

I know this could be a huge topic, but I just wanted = some simple ideas/pointers here.

 

Some documents/links discussing the overall concept = would be great as well.

 

Suresh

------=_NextPart_000_00A6_01C56085.DAE5B050-- --===============2093383971== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid --===============2093383971==-- From rfid-bounces@lists.ietf.org Tue May 24 21:44:08 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DakwK-0004WI-Mz; Tue, 24 May 2005 21:44:08 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DakwI-0004WC-Oq for rfid@megatron.ietf.org; Tue, 24 May 2005 21:44:06 -0400 Received: from ietf-mx.ietf.org (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id VAA15281 for ; Tue, 24 May 2005 21:44:04 -0400 (EDT) Received: from [12.29.89.6] (helo=manh.com) by ietf-mx.ietf.org with esmtp (Exim 4.33) id 1DalEF-0002GI-N3 for rfid@ietf.org; Tue, 24 May 2005 22:03:01 -0400 Received: from ([10.100.100.80]) by relay3.manh.com with SMTP id 4029073.2371184; Tue, 24 May 2005 21:41:15 -0400 Received: from 10.100.101.80 by ma-atl84.manh.com (InterScan E-Mail VirusWall NT); Tue, 24 May 2005 21:36:20 -0400 Received: by MA-ATL80 with Internet Mail Service (5.5.2653.19) id ; Tue, 24 May 2005 21:44:51 -0400 Message-ID: <62E66E667580D61187160004762FCBFA0582EF85@MA-ATL81> From: Howard Kapustein To: "'Suresh Bhaskaran'" , rfid@ietf.org Subject: RE: [Rfid] Reader Discovery Date: Tue, 24 May 2005 21:44:54 -0400 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: multipart/mixed; boundary="----=_NextPartTM-000-2bd74a3f-3fbb-4dcf-9545-69e7e6aaedc8" X-esp: ESP<4>=RBL:<0> RDNS:<0> SHA:<4> UHA:<0> SLS:<0> BAYES:<0> SPF:<0> CAN-SPAM Compliance Dictionary (TRU7a):<0> NigeriaScam Dictionary (TRU7a):<0> Obscenities Dictionary (TRU7a):<0> Spam Dictionary (TRU7a):<0> Porn Dictionary (TRU7a):<0> Embed HTML Dictionary (TRU7a):<0> URL Dictionary (TRU7a):<0> HTML Dictionary (TRU7a):<0> X-Spam-Score: 0.4 (/) X-Scan-Signature: 2d133cc328f58695161c98bb4f4dc213 Cc: X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------=_NextPartTM-000-2bd74a3f-3fbb-4dcf-9545-69e7e6aaedc8 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C560CA.978CFF6C" ------_=_NextPart_001_01C560CA.978CFF6C Content-Type: text/plain >not a whole lot about this in either the RP, or RM or ALE documents of the EPC global either. FYI, "Discovery" was expressly defined *out-of-scope* for RP 1.0. There have been conversations (techies being what they are), but nothing for 1.0. Discovery wasn't a pressing issue (not relative to other things, e.g. a standard way to talk to a reader to get a report of tags read). And a priori configuration requirements weren't (aren't) onerous, realistically. Relatively speaking. Lack of "Discovery" is a far more manageable problem than, say, lack of standard (any) "Management" or "write tag" capabilities. FYI UDP has issues crossing subnets. And there's other options as well. You didn't mention DNS, Novell's thing (ZEN? ZeroNetworking? ZeroConfig? No, that's wrong. Sorry, my brain hurts too much to recall offhand), Apple's Rendezvous, JINI and UPnP, to name a few. >I'm not thinking of any "massively" scalable method for a large number. Why not? That's the truly hard problem. Solutions abound for simple scenarios. And most of them are dead wrong for "massive" scalability. >Some documents/links discussing the overall concept would be great as well. Doesn't IETF have (multiple?) defined protocols for discovery? Which one(s) are considered 'best practices' these days? Where's those "IETF kits" mentioned some weeks ago? - Howard _____ From: rfid-bounces@lists.ietf.org [mailto:rfid-bounces@lists.ietf.org] On Behalf Of Suresh Bhaskaran Sent: Tuesday, May 24, 2005 8:27 PM To: rfid@ietf.org Subject: [Rfid] Reader Discovery One more SLRRP question: What are some simple easy ways (in the "Lightweight" spirit of SLRRP) to do discovery of the reader device? Some options/ideas that seem to have cropped up in various discussions: 1. UDP broadcast 2. DHCP server can give both IP address *and* server address to reader 3. Cisco-type discovery was mentioned as a possibility - I'm not too familiar with this... Is there some document/link that explains this and other options? At this stage, I'm not thinking of any "massively" scalable method for a large number. Simply, if one (or a few) readers come up, what are some ways they can get their IP addresses, and find out who their server is, and start talking to each other? Then the server can send a SLRRP command to get the reader capabilities. I noticed that there was not a whole lot about this in either the RP, or RM or ALE documents of the EPC global either. (I did a search on the word "discover", and didn't find any simple answers relating to the above questions). I know this could be a huge topic, but I just wanted some simple ideas/pointers here. Some documents/links discussing the overall concept would be great as well. Suresh ------_=_NextPart_001_01C560CA.978CFF6C Content-Type: text/html
>not a whole lot about this in either the RP, or RM or ALE documents of the EPC global either.
 
FYI, "Discovery" was expressly defined *out-of-scope* for RP 1.0.
There have been conversations (techies being what they are), but nothing for 1.0.
Discovery wasn't a pressing issue (not relative to other things, e.g. a standard way to talk to a reader to get a report of tags read).
And a priori configuration requirements weren't (aren't) onerous, realistically.
Relatively speaking.
Lack of "Discovery" is a far more manageable problem than, say, lack of standard (any) "Management" or "write tag" capabilities.
 
 
FYI UDP has issues crossing subnets.
And there's other options as well.
You didn't mention DNS, Novell's thing (ZEN? ZeroNetworking? ZeroConfig? No, that's wrong. Sorry, my brain hurts too much to recall offhand), Apple's Rendezvous, JINI and UPnP, to name a few.
 
>I'm not thinking of any "massively" scalable method for a large number.
Why not?
That's the truly hard problem.
Solutions abound for simple scenarios.
And most of them are dead wrong for "massive" scalability.
 
 
>Some documents/links discussing the overall concept would be great as well.
Doesn't IETF have (multiple?) defined protocols for discovery?
Which one(s) are considered 'best practices' these days?
 
Where's those "IETF kits" mentioned some weeks ago? <g>
 
    - Howard
 

From: rfid-bounces@lists.ietf.org [mailto:rfid-bounces@lists.ietf.org] On Behalf Of Suresh Bhaskaran
Sent: Tuesday, May 24, 2005 8:27 PM
To: rfid@ietf.org
Subject: [Rfid] Reader Discovery

One more SLRRP question:

 

What are some simple easy ways (in the "Lightweight" spirit of SLRRP) to do discovery of the reader device?

 

Some options/ideas that seem to have cropped up in various discussions:

 

  1. UDP broadcast
  2. DHCP server can give both IP address *and* server address to reader
  3. Cisco-type discovery was mentioned as a possibility - I'm not too familiar with this...  Is there some document/link that explains this and other options?

 

At this stage, I'm not thinking of any "massively" scalable method for a large number.  Simply, if one (or a few) readers come up, what are some ways they can get their IP addresses, and find out who their server is, and start talking to each other?  Then the server can send a SLRRP command to get the reader capabilities.

 

I noticed that there was not a whole lot about this in either the RP, or RM or ALE documents of the EPC global either. (I did a search on the word "discover", and didn't find any simple answers relating to the above questions).

 

I know this could be a huge topic, but I just wanted some simple ideas/pointers here.

 

Some documents/links discussing the overall concept would be great as well.

 

Suresh

------_=_NextPart_001_01C560CA.978CFF6C-- ------=_NextPartTM-000-2bd74a3f-3fbb-4dcf-9545-69e7e6aaedc8 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid ------=_NextPartTM-000-2bd74a3f-3fbb-4dcf-9545-69e7e6aaedc8-- From rfid-bounces@lists.ietf.org Wed May 25 03:42:07 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DaqWl-0007VO-6y; Wed, 25 May 2005 03:42:07 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1DaqWj-0007VI-KI for rfid@megatron.ietf.org; Wed, 25 May 2005 03:42:05 -0400 Received: from ietf-mx.ietf.org (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id DAA15542 for ; Wed, 25 May 2005 03:42:04 -0400 (EDT) Received: from brmea-mail-4.sun.com ([192.18.98.36]) by ietf-mx.ietf.org with esmtp (Exim 4.33) id 1Daqp2-0004eL-VH for rfid@ietf.org; Wed, 25 May 2005 04:01:03 -0400 Received: from phys-mpk-1 ([129.146.11.81]) by brmea-mail-4.sun.com (8.12.10/8.12.9) with ESMTP id j4P7g20R027380 for ; Wed, 25 May 2005 01:42:02 -0600 (MDT) Received: from conversion-daemon.mpk-mail1.sfbay.sun.com by mpk-mail1.sfbay.sun.com (iPlanet Messaging Server 5.2 HotFix 1.24 (built Dec 19 2003)) id <0IH100B01AW4MR@mpk-mail1.sfbay.sun.com> (original mail from Ricardo.Labiaga@Sun.COM) for rfid@ietf.org; Wed, 25 May 2005 00:42:02 -0700 (PDT) Received: from [129.150.25.167] (vpn-129-150-25-167.SFBay.Sun.COM [129.150.25.167]) by mpk-mail1.sfbay.sun.com (iPlanet Messaging Server 5.2 HotFix 1.24 (built Dec 19 2003)) with ESMTP id <0IH10048S8KG9K@mpk-mail1.sfbay.sun.com>; Tue, 24 May 2005 23:26:40 -0700 (PDT) Date: Tue, 24 May 2005 23:26:39 -0700 From: Ricardo Labiaga Subject: Re: [Rfid] Reader Discovery In-reply-to: <62E66E667580D61187160004762FCBFA0582EF85@MA-ATL81> To: Howard Kapustein Message-id: <42941A9F.5090803@sun.com> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7BIT X-Accept-Language: en-us, en User-Agent: Mozilla Thunderbird 1.0.2 (Windows/20050317) References: <62E66E667580D61187160004762FCBFA0582EF85@MA-ATL81> X-Spam-Score: 0.0 (/) X-Scan-Signature: 2857c5c041d6c02d7181d602c22822c8 Content-Transfer-Encoding: 7BIT Cc: rfid@ietf.org X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org Hello, The EPCglobal Reader Management Working group studied this problem in some detail during its first two months of creation. As Howard points out there are a large number of protocols and technologies that address some pieces of the discovery process in various ways. As a group, we took an initial high level look at UPnP, JXTA, and DHCP. There are many others that we'll need to study as we move into the second version of the Reader Management specification, not only for discovery, but for inter-reader communication/ coordination. - ricardo Howard Kapustein wrote: > />not a whole lot about this in either the RP, or RM or ALE documents of > the EPC global either./ > > FYI, "Discovery" was expressly defined *out-of-scope* for RP 1.0. > There have been conversations (techies being what they are), but nothing > for 1.0. > Discovery wasn't a pressing issue (not relative to other things, e.g. a > standard way to talk to a reader to get a report of tags read). > And a priori configuration requirements weren't (aren't) onerous, > realistically. > Relatively speaking. > Lack of "Discovery" is a far more manageable problem than, say, lack of > standard (any) "Management" or "write tag" capabilities. > > > FYI UDP has issues crossing subnets. > And there's other options as well. > You didn't mention DNS, Novell's thing (ZEN? ZeroNetworking? > ZeroConfig? No, that's wrong. Sorry, my brain hurts too much to recall > offhand), Apple's Rendezvous, JINI and UPnP, to name a few. > > />I'm not thinking of any "massively" scalable method for a large number./ > Why not? > That's the truly hard problem. > Solutions abound for simple scenarios. > And most of them are dead wrong for "massive" scalability. > > > />Some documents/links discussing the overall concept would be great as > well./ > Doesn't IETF have (multiple?) defined protocols for discovery? > Which one(s) are considered 'best practices' these days? > > Where's those "IETF kits" mentioned some weeks ago? > > - Howard > > > ------------------------------------------------------------------------ > *From:* rfid-bounces@lists.ietf.org [mailto:rfid-bounces@lists.ietf.org] > *On Behalf Of *Suresh Bhaskaran > *Sent:* Tuesday, May 24, 2005 8:27 PM > *To:* rfid@ietf.org > *Subject:* [Rfid] Reader Discovery > > One more SLRRP question: > > > > What are some simple easy ways (in the "Lightweight" spirit of SLRRP) to > do discovery of the reader device? > > > > Some options/ideas that seem to have cropped up in various discussions: > > > > 1. UDP broadcast > 2. DHCP server can give both IP address **and** server address to reader > 3. Cisco-type discovery was mentioned as a possibility - I'm not too > familiar with this... Is there some document/link that explains > this and other options? > > > > At this stage, I'm not thinking of any "massively" scalable method for a > large number. Simply, if one (or a few) readers come up, what are some > ways they can get their IP addresses, and find out who their server is, > and start talking to each other? Then the server can send a SLRRP > command to get the reader capabilities. > > > > I noticed that there was not a whole lot about this in either the RP, or > RM or ALE documents of the EPC global either. (I did a search on the > word "discover", and didn't find any simple answers relating to the > above questions). > > > > I know this could be a huge topic, but I just wanted some simple > ideas/pointers here. > > > > Some documents/links discussing the overall concept would be great as well. > > > > Suresh > > > ------------------------------------------------------------------------ > > _______________________________________________ > Rfid mailing list > Rfid@lists.ietf.org > https://www1.ietf.org/mailman/listinfo/rfid _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid From rfid-bounces@lists.ietf.org Wed May 25 11:43:15 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Day2N-0000Ft-JW; Wed, 25 May 2005 11:43:15 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Day2L-0000Fl-HV for rfid@megatron.ietf.org; Wed, 25 May 2005 11:43:13 -0400 Received: from ietf-mx.ietf.org (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id LAA22650 for ; Wed, 25 May 2005 11:43:11 -0400 (EDT) Received: from mse3fe1.mse3.exchange.ms ([69.25.50.165]) by ietf-mx.ietf.org with esmtp (Exim 4.33) id 1DayKl-0000yQ-5W for rfid@ietf.org; Wed, 25 May 2005 12:02:15 -0400 Received: from [192.168.1.44] ([157.130.221.86]) by mse3fe1.mse3.exchange.ms with Microsoft SMTPSVC(6.0.3790.211); Wed, 25 May 2005 11:42:55 -0400 Subject: Re: [Rfid] SLRRP-related questions From: "P. Krishna" To: Suresh Bhaskaran In-Reply-To: <200505242337.j4ONbBqR008971@mail.intelleflex.com> References: <200505242337.j4ONbBqR008971@mail.intelleflex.com> Content-Type: text/plain; charset=iso-8859-13 Message-Id: <1117035775.2903.77.camel@indus> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Wed, 25 May 2005 11:42:55 -0400 Content-Transfer-Encoding: quoted-printable X-OriginalArrivalTime: 25 May 2005 15:42:56.0061 (UTC) FILETIME=[6B944ED0:01C56140] X-Spam-Score: 0.0 (/) X-Scan-Signature: 29dc808194f5fb921c09d0040806d6eb Content-Transfer-Encoding: quoted-printable Cc: rfid@ietf.org X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org On Tue, 2005-05-24 at 19:45, Suresh Bhaskaran wrote: > Krishna, et. al: > Here are some questions I collected up relating to SLRRP: > =20 >=20 > 1. How do you set server IP address and port (into reader) if > reader initiates connection?!=20 > a. (telnet is one way; web server is another?!)=20 This falls into the 'discovery and configuration' bucket and is not a SLRRP protocol issue. In anycase, I can give you a brief overview of how it can be addressed using DHCP. This is one of many ways to do it.=20 A reader upon bootup DHCPs for an IP address. In the DHCP message the reader also requests for a configuration file and maybe a tftp server IP address from where to fetch the config file.=20 The reader configuration file can contain=20 - IP addresses of the upstream RNC(s)=20 - NTP server - operating profile, etc The reader then initiates the connection to the RNC. > 1. What comes back as message sequence number if you have > multiple packet responses per command?=20 > a. E.g. Inventory Access Report=20 Its the message sequence number and not packet sequence number - its not used for re-sequencing. Since we allow multiple outstanding commands in the SLRRP channel, it is useful to correspond the response to the command. An implementation in SLRRP layer may choose to make use of it or not. Especially, for asynchronous responses, the message sequence number has no relevance. If there are multiple packet responses per command, they will contain the same message sequence number. The underlying transport layer (TCP) does the packet sequencing and presents the packets in 'transmitted' order to the SLRRP layer at the receiving end.=20 In the case of inventory-access-report, the message sequence number corresponds only to the inventory command and not to the access command(s). As you might be aware that each access command creates an access-spec at the reader. We can multiple access-specs created at the reader at any time.=20 An inventory command on the other hand, causes the reader to send over-the-air protocol commands to singulate/inventory the population of tags. For any tags matching one or more of the the access-spec(s) stored in the reader, a corresponding access operation (read user memory, lock, etc) on the tag. > 1. Reader Status report comes asynchronously. What is it=FFs > sequence number?=20 > a. (could set to 0)=20 Yes - it is set to 0 and ignored at the receiving end. > 1. What if Reader Status report comes asynchronously? What > happens?=20 The role of SLRRP ends after it has conveyed the reader status report to the RNC. What happens upon receipt of the reader status report, depends on the implementation/logic residing in the RNC. > 1. What happens if Stop Inventory, and there is partial data to > be returned?!=20 A reader upon receiving a "Stop Inventory" command stops sending the over-the-air commands - i.e., stops the singulation/inventory. Its kind of decoupled from when data is sent back to the RNC. The logic in the reader that drives when to send the data back to RNC is determined by the configuration setting conveyed by the "Inventory and Access Reporting Parameter" in "Set Reader Config" command. Let us suppose that the RNC has conveyed to the reader to send the report every inventory round. In the case of a premature termination of an inventory round due to "stop inventory", the reader would declare the round is over, and send the report back. > 1. Why does Access cmd and Inventory Cmd have both Antenna ID=FFs?=20 > Does the Inventory Antenna override the Access Antenna?!=20 A reader can have multiple antennas. Each antenna may be monitoring a different physical region of a facility, each requiring a different setting for inventory parameters (depending on the RF characteristics of the physical coverage area, tag population/mobility, tag protocols to inventory).=20 Likewise, there may be different access operations to be performed by each of these antennas. For example, antenna 1 monitors Dock Door 1 (DD1), antenna 2 monitors Dock Door 2 (DD2). For goods received at DD1, the business logic would like to read the user memory in tags that match pattern 123.*, and for goods shipped from DD2, the business logic would like to read user memory in tags that match pattern 456.*. SLRRP provides a flexibility to set up inventory parameters and access-specs differently and separately for each antenna.=20 No, inventory antenna does not override the access antenna. Inventory and access are decoupled from each other.=20 Inventory is the method to read the tags in the field of view. SLRRP provides the interface to control how that inventory operation is performed by each antenna of the reader.=20 Access commands creates access-specs at the reader which is looked up during inventory rounds to determine if there is any additional tag-memory access operations to be performed. There may be instances where there are access-specs created at the reader. The RNC may have sent an inventory command which sets up the reader to run 'forever' using the inventory-parameters; the reader in turn performs the singulation using the parameters without any subsequent tag-access operations and sends back the inventory report to the RNC. > 1. What if a stop Access is given in the middle of an Inventory > cmd? What happens? Do the Access parameters =B4go away=A1 in th= e > middle of an inventory?=20 Good question. The deleted access-spec will stop taking effect from the next inventory round.=20 Similarly, for a new access-spec, we have text in Section 3.4.9 that states that the new access-spec takes effect starting with the next inventory round. > 1. How do you know how many Inventory Access reports are coming > (suppose a large report is fragmented into smaller pieces)?=20 >=20 We have not specified the format of the inventory access report in V01 of the spec. It'll be addressed in the 02 version of the spec. There will be a bit in the message that indicates if its the last 'piece' of the report. Thanks, /Krishna _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid From rfid-bounces@lists.ietf.org Wed May 25 15:56:41 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Db1zd-00042P-7H; Wed, 25 May 2005 15:56:41 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Db1zc-00042K-62 for rfid@megatron.ietf.org; Wed, 25 May 2005 15:56:40 -0400 Received: from ietf-mx.ietf.org (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id PAA16742 for ; Wed, 25 May 2005 15:56:38 -0400 (EDT) Received: from mse3fe2.mse3.exchange.ms ([69.25.50.167]) by ietf-mx.ietf.org with esmtp (Exim 4.33) id 1Db2I4-0007ff-7C for rfid@ietf.org; Wed, 25 May 2005 16:15:44 -0400 Received: from [192.168.1.45] ([157.130.221.86]) by mse3fe2.mse3.exchange.ms with Microsoft SMTPSVC(6.0.3790.211); Wed, 25 May 2005 15:56:27 -0400 Subject: Re: [Rfid] Reader Discovery From: Scott Barvick To: Suresh Bhaskaran In-Reply-To: <200505250019.j4P0JXg0009393@mail.intelleflex.com> References: <200505250019.j4P0JXg0009393@mail.intelleflex.com> Content-Type: text/plain; charset=UTF-8 Message-Id: <1117050988.8391.131.camel@saco.revasystems.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Wed, 25 May 2005 15:56:28 -0400 Content-Transfer-Encoding: quoted-printable X-OriginalArrivalTime: 25 May 2005 19:56:27.0791 (UTC) FILETIME=[D67A19F0:01C56163] X-Spam-Score: 0.0 (/) X-Scan-Signature: 6cca30437e2d04f45110f2ff8dc1b1d5 Content-Transfer-Encoding: quoted-printable Cc: rfid@ietf.org X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org Suresh, Krishna covered the first steps in his answer about how DHCP can be used. The thing we need to make sure of in SLRRP is that the operations specified support discovery, connection, and operation in large scale deployments. Supporting a model where the reader learns about its RNC through DHCP and then attempts to connect to it is the first step. That will take things a long way, but it obviously requires some amount of manual configuration. We'll pull in others from the IETF to help us move to the next step of automated service location (readers and RNCs) to further reduce the complexity. Scott On Tue, 2005-05-24 at 20:27, Suresh Bhaskaran wrote: > One more SLRRP question: >=20 > =20 >=20 > What are some simple easy ways (in the =E2=80=9CLightweight=E2=80=9D spir= it of SLRRP) > to do discovery of the reader device? >=20 > =20 >=20 > Some options/ideas that seem to have cropped up in various > discussions: >=20 > =20 >=20 > 1. UDP broadcast > 2. DHCP server can give both IP address *and* server address to > reader > 3. Cisco-type discovery was mentioned as a possibility =E2=80=93 I= =E2=80=99m not > too familiar with this=E2=80=A6 Is there some document/link that > explains this and other options? >=20 >=20 > =20 >=20 > At this stage, I=E2=80=99m not thinking of any =E2=80=9Cmassively=E2=80= =9D scalable method for > a large number. Simply, if one (or a few) readers come up, what are > some ways they can get their IP addresses, and find out who their > server is, and start talking to each other? Then the server can send > a SLRRP command to get the reader capabilities. >=20 > =20 >=20 > I noticed that there was not a whole lot about this in either the RP, > or RM or ALE documents of the EPC global either. (I did a search on > the word =E2=80=9Cdiscover=E2=80=9D, and didn=E2=80=99t find any simple a= nswers relating to > the above questions). >=20 > =20 >=20 > I know this could be a huge topic, but I just wanted some simple > ideas/pointers here. >=20 > =20 >=20 > Some documents/links discussing the overall concept would be great as > well. >=20 > =20 >=20 > Suresh >=20 >=20 >=20 > ______________________________________________________________________ > _______________________________________________ > Rfid mailing list > Rfid@lists.ietf.org > https://www1.ietf.org/mailman/listinfo/rfid _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid From rfid-bounces@lists.ietf.org Wed May 25 17:49:13 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Db3kX-0003V0-8v; Wed, 25 May 2005 17:49:13 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Db3kV-0003UW-19 for rfid@megatron.ietf.org; Wed, 25 May 2005 17:49:11 -0400 Received: from ietf-mx.ietf.org (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id RAA01595 for ; Wed, 25 May 2005 17:49:08 -0400 (EDT) Received: from mail.intelleflex.com ([66.236.103.101]) by ietf-mx.ietf.org with esmtp (Exim 4.33) id 1Db42x-0004Gc-BG for rfid@ietf.org; Wed, 25 May 2005 18:08:15 -0400 Received: from SureshLaptopIF (SureshLaptopIF.intelleflex.com [10.1.7.247]) by mail.intelleflex.com (8.13.1/8.13.1) with ESMTP id j4PLfCRZ020854 for ; Wed, 25 May 2005 14:41:12 -0700 Message-Id: <200505252141.j4PLfCRZ020854@mail.intelleflex.com> From: "Suresh Bhaskaran" To: Subject: RE: [Rfid] SLRRP-related questions Date: Wed, 25 May 2005 14:49:08 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook, Build 11.0.6353 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 Thread-Index: AcVhP1XJHhxyGuxBRAu8ThohKB91dwAMwUFg In-Reply-To: <1117035775.2903.77.camel@indus> X-DCC-servers-Metrics: mail 1049; Body=1 Fuz1=1 Fuz2=1 X-Scanned-By: MIMEDefang 2.48 on 10.1.7.25 X-Spam-Score: 2.6 (++) X-Scan-Signature: 33cc095b503da4365ce57c727e553cf1 Content-Transfer-Encoding: 7bit Cc: X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org Thanks Krishna (especially), and Ricardo, Howard, Scott, et. al. The responses, and especially the info on the discovery were very useful. Just to continue the conversation... You (Krishna) mentioned that SLRRP allows multiple outstanding commands in the SLRRP channel. Are multiple TCP/IP connections/sessions also allowed at the Reader? Why or why not? Please note: I'm not trying here to "push" one way or the other. However, I am interested in the thinking process and tradeoffs that went into making these decisions. Also, if a connection is lost, is state (e.g. previous access specs) maintained, or lost or reinitialized? I *really* like the "lightweight" nature of SLRRP, and all the above introduce another level of complexity, and I was just curious as to the current thinking on these issues. Suresh -----Original Message----- From: P. Krishna [mailto:pkrishna@revasystems.com] Sent: Wednesday, May 25, 2005 8:43 AM To: Suresh Bhaskaran Cc: rfid@ietf.org Subject: Re: [Rfid] SLRRP-related questions On Tue, 2005-05-24 at 19:45, Suresh Bhaskaran wrote: > Krishna, et. al: > Here are some questions I collected up relating to SLRRP: > > > 1. How do you set server IP address and port (into reader) if > reader initiates connection?! > a. (telnet is one way; web server is another?!) This falls into the 'discovery and configuration' bucket and is not a SLRRP protocol issue. In anycase, I can give you a brief overview of how it can be addressed using DHCP. This is one of many ways to do it. A reader upon bootup DHCPs for an IP address. In the DHCP message the reader also requests for a configuration file and maybe a tftp server IP address from where to fetch the config file. The reader configuration file can contain - IP addresses of the upstream RNC(s) - NTP server - operating profile, etc The reader then initiates the connection to the RNC. > 1. What comes back as message sequence number if you have > multiple packet responses per command? > a. E.g. Inventory Access Report Its the message sequence number and not packet sequence number - its not used for re-sequencing. Since we allow multiple outstanding commands in the SLRRP channel, it is useful to correspond the response to the command. An implementation in SLRRP layer may choose to make use of it or not. Especially, for asynchronous responses, the message sequence number has no relevance. If there are multiple packet responses per command, they will contain the same message sequence number. The underlying transport layer (TCP) does the packet sequencing and presents the packets in 'transmitted' order to the SLRRP layer at the receiving end. In the case of inventory-access-report, the message sequence number corresponds only to the inventory command and not to the access command(s). As you might be aware that each access command creates an access-spec at the reader. We can multiple access-specs created at the reader at any time. An inventory command on the other hand, causes the reader to send over-the-air protocol commands to singulate/inventory the population of tags. For any tags matching one or more of the the access-spec(s) stored in the reader, a corresponding access operation (read user memory, lock, etc) on the tag. > 1. Reader Status report comes asynchronously. What is it's > sequence number? > a. (could set to 0) Yes - it is set to 0 and ignored at the receiving end. > 1. What if Reader Status report comes asynchronously? What > happens? The role of SLRRP ends after it has conveyed the reader status report to the RNC. What happens upon receipt of the reader status report, depends on the implementation/logic residing in the RNC. > 1. What happens if Stop Inventory, and there is partial data to > be returned?! A reader upon receiving a "Stop Inventory" command stops sending the over-the-air commands - i.e., stops the singulation/inventory. Its kind of decoupled from when data is sent back to the RNC. The logic in the reader that drives when to send the data back to RNC is determined by the configuration setting conveyed by the "Inventory and Access Reporting Parameter" in "Set Reader Config" command. Let us suppose that the RNC has conveyed to the reader to send the report every inventory round. In the case of a premature termination of an inventory round due to "stop inventory", the reader would declare the round is over, and send the report back. > 1. Why does Access cmd and Inventory Cmd have both Antenna ID's? > Does the Inventory Antenna override the Access Antenna?! A reader can have multiple antennas. Each antenna may be monitoring a different physical region of a facility, each requiring a different setting for inventory parameters (depending on the RF characteristics of the physical coverage area, tag population/mobility, tag protocols to inventory). Likewise, there may be different access operations to be performed by each of these antennas. For example, antenna 1 monitors Dock Door 1 (DD1), antenna 2 monitors Dock Door 2 (DD2). For goods received at DD1, the business logic would like to read the user memory in tags that match pattern 123.*, and for goods shipped from DD2, the business logic would like to read user memory in tags that match pattern 456.*. SLRRP provides a flexibility to set up inventory parameters and access-specs differently and separately for each antenna. No, inventory antenna does not override the access antenna. Inventory and access are decoupled from each other. Inventory is the method to read the tags in the field of view. SLRRP provides the interface to control how that inventory operation is performed by each antenna of the reader. Access commands creates access-specs at the reader which is looked up during inventory rounds to determine if there is any additional tag-memory access operations to be performed. There may be instances where there are access-specs created at the reader. The RNC may have sent an inventory command which sets up the reader to run 'forever' using the inventory-parameters; the reader in turn performs the singulation using the parameters without any subsequent tag-access operations and sends back the inventory report to the RNC. > 1. What if a stop Access is given in the middle of an Inventory > cmd? What happens? Do the Access parameters "go away" in the > middle of an inventory? Good question. The deleted access-spec will stop taking effect from the next inventory round. Similarly, for a new access-spec, we have text in Section 3.4.9 that states that the new access-spec takes effect starting with the next inventory round. > 1. How do you know how many Inventory Access reports are coming > (suppose a large report is fragmented into smaller pieces)? > We have not specified the format of the inventory access report in V01 of the spec. It'll be addressed in the 02 version of the spec. There will be a bit in the message that indicates if its the last 'piece' of the report. Thanks, /Krishna _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid From rfid-bounces@lists.ietf.org Wed May 25 18:39:57 2005 Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Db4Xd-00042r-AG; Wed, 25 May 2005 18:39:57 -0400 Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1Db4Xa-00042b-6z for rfid@megatron.ietf.org; Wed, 25 May 2005 18:39:55 -0400 Received: from ietf-mx.ietf.org (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id SAA05439 for ; Wed, 25 May 2005 18:39:51 -0400 (EDT) Received: from mse3fe1.mse3.exchange.ms ([69.25.50.165]) by ietf-mx.ietf.org with esmtp (Exim 4.33) id 1Db4q3-0005FH-ER for rfid@ietf.org; Wed, 25 May 2005 18:58:59 -0400 Received: from [192.168.1.44] ([157.130.221.86]) by mse3fe1.mse3.exchange.ms with Microsoft SMTPSVC(6.0.3790.211); Wed, 25 May 2005 18:14:34 -0400 Subject: RE: [Rfid] SLRRP-related questions From: "P. Krishna" To: Suresh Bhaskaran In-Reply-To: <200505252141.j4PLfCRZ020854@mail.intelleflex.com> References: <200505252141.j4PLfCRZ020854@mail.intelleflex.com> Content-Type: text/plain Message-Id: <1117059274.2903.98.camel@indus> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Wed, 25 May 2005 18:14:34 -0400 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 25 May 2005 22:14:34.0933 (UTC) FILETIME=[21FF9E50:01C56177] X-Spam-Score: 0.0 (/) X-Scan-Signature: a492040269d440726bfd84680622cee7 Content-Transfer-Encoding: 7bit Cc: rfid@ietf.org X-BeenThere: rfid@lists.ietf.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "RFID Reader Operations, Management, and Administration Discussion List" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: rfid-bounces@lists.ietf.org Errors-To: rfid-bounces@lists.ietf.org > Are multiple TCP/IP connections/sessions also allowed at the Reader? Why or > why not? SLRRP does not have a "session ID". By definition, a SLRRP channel is a single session. If the Reader allows multiple SLRRP channels to exist, then it is the responsibility of the Reader's design to handle it and is outside the scope of SLRRP. To be clear, SLRRP does not require multiple sessions to be opened. > Also, if a connection is lost, is state (e.g. previous access specs) > maintained, or lost or reinitialized? > That is beyond SLRRP too! SLRRP is an interface protocol - its stateless. Its an end-node issue. The host and the reader are stateful and should be keeping the state until and unless the node got reset/rebooted or state-update from the other end-node. > I *really* like the "lightweight" nature of SLRRP, and all the above > introduce another level of complexity, and I was just curious as to the > current thinking on these issues. I am not inclined to add any complexity. If you think handling multiple commands in flight is an issue, then lets discuss that. Here are my thoughts ... Some Readers internally have a serialized architecture (single threaded), thereby allowing only a single command to be processed at a time. This means the commands may need to buffered at the receive interface of the Reader. All the commands in SLRRP from the host require an response from the reader. If the host chose to send multiple commands, then it is the host's responsibility to keep track of the command fulfillment @ the reader. Allowing multiple commands in flight in an network interface protocol does not (and should not) force multi-threaded design in a reader. On the same token, a single-threaded reader design should not force the interface protocol to be serialized (i.e., only one unacked command in flight). I hope this helps. Thanks, /Krishna > > Suresh > > -----Original Message----- > From: P. Krishna [mailto:pkrishna@revasystems.com] > Sent: Wednesday, May 25, 2005 8:43 AM > To: Suresh Bhaskaran > Cc: rfid@ietf.org > Subject: Re: [Rfid] SLRRP-related questions > > > > On Tue, 2005-05-24 at 19:45, Suresh Bhaskaran wrote: > > Krishna, et. al: > > Here are some questions I collected up relating to SLRRP: > > > > > > 1. How do you set server IP address and port (into reader) if > > reader initiates connection?! > > a. (telnet is one way; web server is another?!) > > This falls into the 'discovery and configuration' bucket and is not a > SLRRP protocol issue. In anycase, I can give you a brief overview of how > it can be addressed using DHCP. This is one of many ways to do it. > > A reader upon bootup DHCPs for an IP address. In the DHCP message the > reader also requests for a configuration file and maybe a tftp server IP > address from where to fetch the config file. > > The reader configuration file can contain > - IP addresses of the upstream RNC(s) > - NTP server > - operating profile, etc > > The reader then initiates the connection to the RNC. > > > 1. What comes back as message sequence number if you have > > multiple packet responses per command? > > a. E.g. Inventory Access Report > > Its the message sequence number and not packet sequence number - its not > used for re-sequencing. Since we allow multiple outstanding commands in > the SLRRP channel, it is useful to correspond the response to the > command. An implementation in SLRRP layer may choose to make use of it > or not. Especially, for asynchronous responses, the message sequence > number has no relevance. > > If there are multiple packet responses per command, they will contain > the same message sequence number. The underlying transport layer (TCP) > does the packet sequencing and presents the packets in 'transmitted' > order to the SLRRP layer at the receiving end. > > In the case of inventory-access-report, the message sequence number > corresponds only to the inventory command and not to the access > command(s). As you might be aware that each access command creates an > access-spec at the reader. We can multiple access-specs created at the > reader at any time. > > An inventory command on the other hand, causes the reader to send > over-the-air protocol commands to singulate/inventory the population of > tags. For any tags matching one or more of the the access-spec(s) stored > in the reader, a corresponding access operation (read user memory, lock, > etc) on the tag. > > > > > 1. Reader Status report comes asynchronously. What is it's > > sequence number? > > a. (could set to 0) > > Yes - it is set to 0 and ignored at the receiving end. > > > > 1. What if Reader Status report comes asynchronously? What > > happens? > > The role of SLRRP ends after it has conveyed the reader status report to > the RNC. What happens upon receipt of the reader status report, depends > on the implementation/logic residing in the RNC. > > > > 1. What happens if Stop Inventory, and there is partial data to > > be returned?! > A reader upon receiving a "Stop Inventory" command stops sending the > over-the-air commands - i.e., stops the singulation/inventory. > > Its kind of decoupled from when data is sent back to the RNC. > > The logic in the reader that drives when to send the data back to RNC is > determined by the configuration setting conveyed by the "Inventory and > Access Reporting Parameter" in "Set Reader Config" command. Let us > suppose that the RNC has conveyed to the reader to send the report every > inventory round. In the case of a premature termination of an inventory > round due to "stop inventory", the reader would declare the round is > over, and send the report back. > > > > 1. Why does Access cmd and Inventory Cmd have both Antenna ID's? > > Does the Inventory Antenna override the Access Antenna?! > A reader can have multiple antennas. Each antenna may be monitoring a > different physical region of a facility, each requiring a different > setting for inventory parameters (depending on the RF characteristics of > the physical coverage area, tag population/mobility, tag protocols to > inventory). > > Likewise, there may be different access operations to be performed by > each of these antennas. For example, antenna 1 monitors Dock Door 1 > (DD1), antenna 2 monitors Dock Door 2 (DD2). For goods received at DD1, > the business logic would like to read the user memory in tags that match > pattern 123.*, and for goods shipped from DD2, the business logic would > like to read user memory in tags that match pattern 456.*. > > SLRRP provides a flexibility to set up inventory parameters and > access-specs differently and separately for each antenna. > > No, inventory antenna does not override the access antenna. > Inventory and access are decoupled from each other. > > Inventory is the method to read the tags in the field of view. SLRRP > provides the interface to control how that inventory operation is > performed by each antenna of the reader. > Access commands creates access-specs at the reader which is looked up > during inventory rounds to determine if there is any additional > tag-memory access operations to be performed. > > There may be instances where there are access-specs created at the > reader. The RNC may have sent an inventory command which sets up the > reader to run 'forever' using the inventory-parameters; the reader in > turn performs the singulation using the parameters without any > subsequent tag-access operations and sends back the inventory report to > the RNC. > > > > 1. What if a stop Access is given in the middle of an Inventory > > cmd? What happens? Do the Access parameters "go away" in the > > middle of an inventory? > > Good question. > > The deleted access-spec will stop taking effect from the next inventory > round. > > Similarly, for a new access-spec, we have text in Section 3.4.9 that > states that the new access-spec takes effect starting with the next > inventory round. > > > > 1. How do you know how many Inventory Access reports are coming > > (suppose a large report is fragmented into smaller pieces)? > > > We have not specified the format of the inventory access report in V01 > of the spec. It'll be addressed in the 02 version of the spec. There > will be a bit in the message that indicates if its the last 'piece' of > the report. > > Thanks, > /Krishna > > > _______________________________________________ > Rfid mailing list > Rfid@lists.ietf.org > https://www1.ietf.org/mailman/listinfo/rfid _______________________________________________ Rfid mailing list Rfid@lists.ietf.org https://www1.ietf.org/mailman/listinfo/rfid