Subject: [forces] LFB lib 05 version comments #1

From: Jamal Hadi Salim <[email-masked]>
Date: Sun, 7 Aug 2011 12:28:32 -0400

Preamble:
As promised here are some comments. I will send this in a series of
emails to make the discussion more manageable.
I have many comments - so lets please move fast so we can shoot
for a new publication.

comments:

1) This is a general comment i made in the previous release.
The change did not make it in properly.

a) Define what is a downstream and upstream LFB means.
While the terms are mostly used (with exception of a few places),
the definition needs to be in place. Put either in beginning of
section 5 or in section 2.

b) Be very precise about the different meanings of LFB port vs
physical port vs virtual interface port etc.
I would suggest you audit the document in full and fix this.

2) Other general comments:
a) please be consistent in the document in your usage of terms.
i) next-hop vs nexthop vs next hop

b) InvalidIPv4SrcAddrCasexxx
I believe there are proper terms for these terms. Can we find
the proper terms and replace these generic terms?
Example appropriate terms are "martian" and "bogon" packets.

c) Section 5 text has improved greatly - general comments
(more specific comments to come later):
i ) In "data handling" sections, often the text mentions a table
but does not mention what is the lookup key or index that is
used to look at this table.

ii) There is a lot of repetion of text between the data handling and
description of the LFBs. The data handling should be describing
things in general and may reference components. The component section
on the other hand should not try so hard to describe the data handling.

cheers,
jamal

---

From: "Wang,Weiming" <[email-masked]>
Date: Mon, 8 Aug 2011 22:25:52 +0800

Jamal,

Thanks very much for the valuable comments. Pls see inline the responses.

thanks,
Weiming

--------------------------------------------------
From: "Jamal Hadi Salim" <[email-masked]>
Subject: [SPAM] LFB lib 05 version comments #1

> section 5 or in section 2.
Ok, this will be done soon.

> I would suggest you audit the document in full and fix this.
I'l try to give a description on  the different meanings of the kinds of 
ports soon.

> i) next-hop vs nexthop vs next hop
Ok.

> Example appropriate terms are "martian" and "bogon" packets.
Chuanhuang: pls try to find out the terms for the invalid packets.

> used to look at this table.
Chuanhuang: could you give a list of the tables with the index or lookup key 
if any, then I'l add the text to the table description.
Evangelos: if you are also possible to provide some, pls just send me, 
thanks.

> on the other hand should not try so hard to describe the data handling.
Yes, we need to refurbish the text. Whereas, we may have to face the fact 
that the text for data handling and the components are in many cases highly 
cross referred. For data handling, it is very hard to describe things clear 
enough without explaining some components. For some components, it is hard 
to make clear without saying its function to data, which is actually on data 
handling.

---

From: "Wang,Weiming" <[email-masked]>
Date: Tue, 16 Aug 2011 09:14:28 +0800

Hi all, especially Joel and Jamal, 

A section as below is added in section 5.0. :

In this section, the terminology of an upstream LFB or a downstream LFB may be used. When describing a current LFB, an upstream LFB refers to an LFB which is connected to current LFB via data paths and output data packets to current LFB. A downstream LFB refers to an LFB which is connected to current LFB via data paths and receives data packets output from current LFB. 

As for various ports meanings,  I'm going to add definitions in the Definition (section 2) as below: 

LFB Port - A port refers to an LFB input port or output port. See Section 3.2 of RFC 5812 [5812] for more detailed definitions.
 
Physical Port - A port refers to a physical media input port or output port of an FE. A physical port is usually assigned with a physical port ID, abbreviated with a PHYPortID. This document mainly deals with physical ports with Ethernet media.
 
Logical Port - A conceptually virtual port at data link layer (L2) or network layer (L3). A logical port is usually assigned with a logical port ID, abbreviated with a LogicalPortID. The logical ports can be further categorized with a L2 logical port or a L3 logical port. An L2 logical port can be assigned with a L2 logical port ID, abbreviated with a L2PortID. An L3 logical port can be assigned with a L3 logical port ID, abbreviated with a L3PortID. MAC layer VLAN ports belongs to L2 logical ports as well as logical ports. 

Pls comment on the changes.

Chuanhuang (and Evangelos if possible) : pls reply other items of the Jamal's comemnts in this email.

thanks,
Weiming

---

From: "Joel M. Halpern" <[email-masked]>
Date: Mon, 15 Aug 2011 22:13:37 -0400

> A section as below is added in section 5.0. :
Your proposed:

In this section, the terminology of an upstream LFB or a downstream LFB 
may be used. When describing a current LFB, an upstream LFB refers to an 
LFB which is connected to current LFB via data paths and output data 
packets to current LFB. A downstream LFB refers to an LFB which is 
connected to current LFB via data paths and receives data packets output 
from current LFB.

May I suggest:
In this section, the terms "upstream LFB" and "downstream LFB" are used. 
  These are used relative to an LFB to an LFB that is being described. 
An "upstream LFB" is one whose output ports are connected to input ports 
of the LFB under consideration such that output (typically packets with 
metadata) can be sent from the "upstream LFB" to the LFB under 
consideration.  Similarly, a "downstream LFB" whose input ports are 
connected to output ports of the LFB under consideration such that the 
LFB under consideration can send information to the "downstream LFB". 
Note that in some rare topologies, an LFB may be both upstream and 
downstream relative to another LFB.

Yours,
Joel

---

From: "Wang,Weiming" <[email-masked]>
Date: Tue, 16 Aug 2011 10:21:15 +0800

Hi Joel, 

Thanks for the propose. I'v included the change in. 
Can you also help to check the definitions on the various ports in another email, which I think are also very important? 

thanks,
Weiming

---

From: Joel <[email-masked]>
Date: Mon, 15 Aug 2011 23:22:48 -0400

The definitions looked pretty good to me.  I am sure Jamal will check 
them as well, and he is better than I at spotting subtle (but often 
important) points.

Yours,
Joel

On 8/15/2011 10:21 PM, Wang,Weiming wrote:
> From: "Joel M. Halpern"<[email-masked]>
> _______________________________________________
> forces mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/forces