From owner-malloc@catarina.usc.edu Thu Mar 8 15:13:19 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id PAA11287 for ; Thu, 8 Mar 2001 15:13:11 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id LAA60532 for malloc-list; Thu, 8 Mar 2001 11:46:05 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from rumi.usc.edu (rumi.usc.edu [128.125.51.41]) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id LAA60527; Thu, 8 Mar 2001 11:46:00 -0800 (PST) Received: from rumi (localhost [127.0.0.1]) by rumi.usc.edu (8.9.3/8.9.3) with ESMTP id LAA83057; Thu, 8 Mar 2001 11:45:59 -0800 (PST) Message-Id: <200103081945.LAA83057@rumi.usc.edu> To: Ali Boudani cc: idmr@cs.ucl.ac.uk, malloc@catarina.usc.edu Subject: Re: MASC In-reply-to: Your message of "Thu, 08 Mar 2001 10:51:47 +0100." <3AA75633.36575261@irisa.fr> Date: Thu, 08 Mar 2001 11:45:59 -0800 From: Pavlin Ivanov Radoslavov Sender: owner-malloc@catarina.usc.edu Precedence: bulk [A better place to ask MASC-related questions is malloc@catarina.usc.edu (CC-ed above). If someone replies to this email, please remove IDMR from the CC list] > Hello, > What is the difference between the claim-collide and query response in > MASC?? Just to clarify, MASC uses only the claim-collide mechanism. > I read the MASC protocl and I didnt understand it?? > will any one please explain it to me. > thanx you The spec purpose is more or less to describe the protocol the way it is, hence it doesn't go into details about alternative solutions. The main difference between claim-collide and query-response (also occasionally called request-response) is: With query-response, if you want to get/use some resource (e.g., name or block of addresses), you must request it from a resource manager. Only after you get a positive acknowledgment from the manager, then you can go ahead and use the resource. If the manager is down or not reachable, then the allocation system needs to consider how to deal with robustness issues instead of keeping you waiting. With claim-collide, there is no explicit manager responsible for the resource allocation. If you want to use some resource, you shout loudly to everyone "I WANT THAT!". Then you politely wait for long enough interval of time to make sure that everyone heard you and that nobody else wanted the same resource. If you hear somebody else asking for the same resource, then the collision is resolved unambiguously (e.g. based on timestamp or whatever). If you are the loser then you must repeat the process by claiming something else. After you have waited long enough time without a collision (or if you are the winner of all collisions), then you pretty confidently assume that you can use that resource. Hope that helps, Pavlin From owner-malloc@catarina.usc.edu Mon Mar 12 16:02:22 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id QAA20154 for ; Mon, 12 Mar 2001 16:02:18 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id MAA79162 for malloc-list; Mon, 12 Mar 2001 12:29:16 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from rumi.usc.edu (rumi.usc.edu [128.125.51.41]) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id MAA79157 for ; Mon, 12 Mar 2001 12:29:16 -0800 (PST) Received: (from pavlin@localhost) by rumi.usc.edu (8.9.3/8.9.3) id MAA22054 for malloc@catarina.usc.edu; Mon, 12 Mar 2001 12:29:15 -0800 (PST) Received: from usc.edu (root@usc.edu [128.125.253.136] (may be forged)) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id GAA77611; Mon, 12 Mar 2001 06:18:15 -0800 (PST) Received: from sky.irisa.fr (sky.irisa.fr [131.254.60.147]) by usc.edu (8.9.3.1/8.9.3/usc) with ESMTP id GAA11953; Mon, 12 Mar 2001 06:18:14 -0800 (PST) Received: from irisa.fr (rocha.irisa.fr [131.254.13.52]) by sky.irisa.fr (8.9.3/8.9.3) with ESMTP id PAA15006; Mon, 12 Mar 2001 15:14:28 +0100 (MET) Message-ID: <3AACD9C4.D4A96E9D@irisa.fr> Date: Mon, 12 Mar 2001 15:14:28 +0100 From: Ali Boudani Organization: INRIA - RENNES X-Mailer: Mozilla 4.75 [en] (WinNT; U) X-Accept-Language: en, fr MIME-Version: 1.0 To: Pavlin Ivanov Radoslavov CC: malloc@catarina.usc.edu Subject: Re: MASC References: <200103081945.LAA83057@rumi.usc.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-malloc@catarina.usc.edu Precedence: bulk Content-Transfer-Encoding: 7bit Hello, my question is so simple: why in the MBGP/PIM-SM/MSDP solution for the problem of multicast we didnt use the allocation of addresses. Why BGMP need the use of MASC and the MBGP/PIM-SM/MSDP doesnt need it thanx Pavlin Ivanov Radoslavov wrote: > [A better place to ask MASC-related questions is > malloc@catarina.usc.edu (CC-ed above). > If someone replies to this email, please remove IDMR from the > CC list] > > > Hello, > > What is the difference between the claim-collide and query response in > > MASC?? > > Just to clarify, MASC uses only the claim-collide mechanism. > > > I read the MASC protocl and I didnt understand it?? > > will any one please explain it to me. > > thanx you > > The spec purpose is more or less to describe the protocol the way it > is, hence it doesn't go into details about alternative solutions. > > The main difference between claim-collide and query-response (also > occasionally called request-response) is: > > With query-response, if you want to get/use some resource (e.g., > name or block of addresses), you must request it from a resource > manager. Only after you get a positive acknowledgment from the > manager, then you can go ahead and use the resource. If the manager > is down or not reachable, then the allocation system needs to > consider how to deal with robustness issues instead of keeping you > waiting. > > With claim-collide, there is no explicit manager responsible for > the resource allocation. If you want to use some resource, you > shout loudly to everyone "I WANT THAT!". Then you politely wait for > long enough interval of time to make sure that everyone heard you > and that nobody else wanted the same resource. If you hear somebody > else asking for the same resource, then the collision is resolved > unambiguously (e.g. based on timestamp or whatever). If you are > the loser then you must repeat the process by claiming something > else. > After you have waited long enough time without a collision (or if > you are the winner of all collisions), then you pretty confidently > assume that you can use that resource. > > Hope that helps, > Pavlin From owner-malloc@catarina.usc.edu Mon Mar 12 22:34:38 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id WAA29912 for ; Mon, 12 Mar 2001 22:34:36 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id TAA80933 for malloc-list; Mon, 12 Mar 2001 19:15:51 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from rumi.usc.edu (rumi.usc.edu [128.125.51.41]) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id TAA80928; Mon, 12 Mar 2001 19:15:47 -0800 (PST) Received: from rumi (localhost [127.0.0.1]) by rumi.usc.edu (8.9.3/8.9.3) with ESMTP id TAA23792; Mon, 12 Mar 2001 19:15:46 -0800 (PST) Message-Id: <200103130315.TAA23792@rumi.usc.edu> To: Ali Boudani cc: malloc@catarina.usc.edu Subject: Re: MASC In-reply-to: Your message of "Mon, 12 Mar 2001 15:14:28 +0100." <3AACD9C4.D4A96E9D@irisa.fr> Date: Mon, 12 Mar 2001 19:15:46 -0800 From: Pavlin Ivanov Radoslavov Sender: owner-malloc@catarina.usc.edu Precedence: bulk > my question is so simple: > why in the MBGP/PIM-SM/MSDP solution for the problem of multicast we didnt > use the allocation of addresses. > Why BGMP need the use of MASC and the MBGP/PIM-SM/MSDP doesnt need it > thanx MASC is not a MUST for BGMP. It is just one possible solution for creating the association "mcast address prefix"<->"domain" which is needed by BGMP. Creating this association can be seen as a side-effect of the way MASC works. So, you can have BGMP without MASC if you have some other mechanism to create the above association. In PIM-SM for example, the Bootstrap mechanism is the mechanism used to create the "mcast address prefix"<->RP association, but there are some other mechanisms as well. BGMP, similar to all other mcast. routing protocols doesn't not care about mcast address allocation, because the address allocation is an application-area related issue. Similarly, MASC doesn't care about BGMP, and can work without it. Regards, Pavlin From owner-malloc@catarina.usc.edu Thu Mar 15 10:02:41 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id KAA00744 for ; Thu, 15 Mar 2001 10:02:38 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id GAA93168 for malloc-list; Thu, 15 Mar 2001 06:39:02 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from usc.edu (root@usc.edu [128.125.253.136] (may be forged)) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id GAA93163 for ; Thu, 15 Mar 2001 06:39:01 -0800 (PST) Received: from public.bjnet.edu.cn (public.bjnet.edu.cn [202.112.55.66]) by usc.edu (8.9.3.1/8.9.3/usc) with ESMTP id GAA26148 for ; Thu, 15 Mar 2001 06:38:53 -0800 (PST) Received: from cernetfrank (compass12.compass.edu.cn [202.112.55.99]) by public.bjnet.edu.cn (8.8.8/8.8.8) with SMTP id WAA20281 for ; Thu, 15 Mar 2001 22:18:37 +0800 (CST) Message-ID: <014301c0ad5d$04f40a80$633770ca@cernetfrank> Reply-To: "Lu Guohan" From: "Lu Guohan" To: Subject: What is the future of MAAA Date: Thu, 15 Mar 2001 22:34:18 +0800 Organization: CERNET(China Education and Research Network) MIME-Version: 1.0 Content-Type: text/plain; charset="gb2312" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6700 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6700 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by catarina.usc.edu id GAA93164 Sender: owner-malloc@catarina.usc.edu Precedence: bulk Content-Transfer-Encoding: 8bit Dear sir, I am right now a graduate student. I am currently very interested in MAAA, and want to do some research work on it. But I have a few questions and want to get some advice on my future research work. 1.MAAA is now the dynamic solution on multicast address allocation. It may be used in the MSDP/PIM-SM/BGP+ inter-domain multicast routing architecture, since the MASC/BGMP is not consider to be deploy in ipv4. But right now SSM is consider to be deployed in ipv4. Since SSM have a lot of advantage over the traditional open group model, Somebody say that SSM is expected to be the major protocol for IPv4. It is true? If it is true then MAAA will not be widely deployed, it that right? 2.GLOP is propose to be another solution to the address problem. Even it is thought to be a temporary one, it is very simple. It said that ISP prefer it because MAAA is so complex. 3.As a lot of components in MAAA are right now RFCs and Internet-Drafts. What will be the future focus on MAAA, or broadly speaking what will be the future focus on multicast address allocation. I wonder what kinds of research work can be done or just let the ISP to deploy it. Thank you for all. I am looking forward to your suggestions and advices. Guohan Lu CERNET From owner-malloc@catarina.usc.edu Thu Mar 15 14:50:59 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id OAA06532 for ; Thu, 15 Mar 2001 14:50:57 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id LAA93993 for malloc-list; Thu, 15 Mar 2001 11:25:35 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from usc.edu (root@usc.edu [128.125.253.136] (may be forged)) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id LAA93988 for ; Thu, 15 Mar 2001 11:25:34 -0800 (PST) Received: from sky.irisa.fr (sky.irisa.fr [131.254.60.147]) by usc.edu (8.9.3.1/8.9.3/usc) with ESMTP id LAA16475 for ; Thu, 15 Mar 2001 11:25:33 -0800 (PST) Received: from irisa.fr (rocha.irisa.fr [131.254.13.52]) by sky.irisa.fr (8.9.3/8.9.3) with ESMTP id UAA04964; Thu, 15 Mar 2001 20:21:00 +0100 (MET) Message-ID: <3AB11624.3942A7A7@irisa.fr> Date: Thu, 15 Mar 2001 20:21:08 +0100 From: Ali Boudani Organization: INRIA - RENNES X-Mailer: Mozilla 4.75 [en] (WinNT; U) X-Accept-Language: en, fr MIME-Version: 1.0 To: Lu Guohan CC: malloc@catarina.usc.edu Subject: Re: What is the future of MAAA References: <014301c0ad5d$04f40a80$633770ca@cernetfrank> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-malloc@catarina.usc.edu Precedence: bulk Content-Transfer-Encoding: 7bit I have also some questions on your questions, so any one will answer can answer us both. thanx > 1.MAAA is now the dynamic solution on multicast address allocation. It may be used in the MSDP/PIM-SM/BGP+ inter-domain multicast routing architecture, Is this true , why do we need address allocation for this type?? I mean why a stricte address allocation for this type?? > since the MASC/BGMP is not consider to be deploy in ipv4. Isnt MASC/BGMP was the a long term solution that replaced the MSDP/PIM-SM/MBGP. > But right now SSM is consider to be deployed in ipv4. Since SSM have a lot of advantage over the traditional open group model, Somebody say that SSM is expected to be the major protocol for IPv4. It is true? If it is true then MAAA will not be widely deployed, it that right? I didnt understand one thing. Why SSM is very important and as I know it is just a specif case of PI-SM , so cant we say that SSM is a particular case of PIM-SM. So what about the sources that dont belong to the range of SSM. Shouldnt wwe consider it as a multicast sources ?? thanx From owner-malloc@catarina.usc.edu Fri Mar 16 04:18:54 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id EAA01022 for ; Fri, 16 Mar 2001 04:18:53 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id BAA97417 for malloc-list; Fri, 16 Mar 2001 01:01:03 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from usc.edu (root@usc.edu [128.125.253.136] (may be forged)) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id BAA97412 for ; Fri, 16 Mar 2001 01:01:02 -0800 (PST) Received: from sky.irisa.fr (sky.irisa.fr [131.254.60.147]) by usc.edu (8.9.3.1/8.9.3/usc) with ESMTP id BAA25313 for ; Fri, 16 Mar 2001 01:01:01 -0800 (PST) Received: from irisa.fr (rocha.irisa.fr [131.254.13.52]) by sky.irisa.fr (8.9.3/8.9.3) with ESMTP id JAA22239; Fri, 16 Mar 2001 09:42:13 +0100 (MET) Message-ID: <3AB1D1E5.A00CABCF@irisa.fr> Date: Fri, 16 Mar 2001 09:42:13 +0100 From: Ali Boudani Organization: INRIA - RENNES X-Mailer: Mozilla 4.75 [en] (WinNT; U) X-Accept-Language: en, fr MIME-Version: 1.0 To: ssm-interest@external.cisco.com, malloc@catarina.usc.edu, idmr@cs.ucl.ac.uk Subject: hello Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-malloc@catarina.usc.edu Precedence: bulk Content-Transfer-Encoding: 7bit I was wondering that SSM (before was the SImple Muticast or EXPRESS) use a channel like (S, G) and the drafts are saying that this is the solution to the address allocation problem because each group is represented with the souce address also. but why?? figure this : 2 groups (having the same address) want to recieve from the same source. the (simple multicast or EXPRESS or SSM) will consider them as the same group So in this case any (S, G) = (S, G1) .... (S, Gn) and there is no sense in the adress group of the recievers. at the same time if G2 (the recievers in the G2 but having the G multicast address group) for example want to recieve from S2 , in that case all the G1.... Gn will recieve the data. am I right ?? thanx From owner-malloc@catarina.usc.edu Fri Mar 16 14:47:35 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id OAA09400 for ; Fri, 16 Mar 2001 14:47:29 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id LAA00188 for malloc-list; Fri, 16 Mar 2001 11:26:15 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from rumi.usc.edu (rumi.usc.edu [128.125.51.41]) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id LAA00183 for ; Fri, 16 Mar 2001 11:26:14 -0800 (PST) Received: (from pavlin@localhost) by rumi.usc.edu (8.9.3/8.9.3) id LAA58121 for malloc@catarina.usc.edu; Fri, 16 Mar 2001 11:26:14 -0800 (PST) Received: from usc.edu (root@usc.edu [128.125.253.136]) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id BAA97590 for ; Fri, 16 Mar 2001 01:56:16 -0800 (PST) Received: from relay1.alcatel.be (alc119.alcatel.be [195.207.101.119]) by usc.edu (8.9.3.1/8.9.3/usc) with ESMTP id BAA18883 for ; Fri, 16 Mar 2001 01:56:15 -0800 (PST) Received: from Bemail06.net.alcatel.be (localhost [127.0.0.1]) by relay1.alcatel.be (8.10.1/8.10.1) with SMTP id f2G9aMv01866; Fri, 16 Mar 2001 10:36:22 +0100 (MET) Received: from alcatel.be ([138.203.65.20]) by Bemail06.net.alcatel.be (Lotus SMTP MTA v4.6.7 (934.1 12-30-1999)) with SMTP id C1256A11.0034BD5E; Fri, 16 Mar 2001 10:36:03 +0100 Message-ID: <3AB1DE82.D6ADD1AB@alcatel.be> Date: Fri, 16 Mar 2001 10:36:02 +0100 From: Dirk Ooms X-Mailer: Mozilla 4.61 [en] (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: Ali Boudani CC: ssm-interest@external.cisco.com, malloc@catarina.usc.edu, idmr@cs.ucl.ac.uk Subject: Re: hello References: <3AB1D1E5.A00CABCF@irisa.fr> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-malloc@catarina.usc.edu Precedence: bulk Content-Transfer-Encoding: 7bit Ali Boudani wrote: > > I was wondering that SSM (before was the SImple Muticast or EXPRESS) use > a channel like (S, G) and the drafts are saying that this is the > solution to the address allocation problem because each group is > represented with the souce address also. but why?? > figure this : 2 groups (having the same address) want to recieve from > the same source. I have difficulty in understanding what you are writing, but I think that the main point that you are missing is that a sender will never use the same group address for two different streams. The sender determines wich G to use for a certain stream. dirk the (simple multicast or EXPRESS or SSM) will consider > them as the same group > So in this case any (S, G) = (S, G1) .... (S, Gn) and there is no sense > in the adress group of the recievers. > at the same time if G2 (the recievers in the G2 but having the G > multicast address group) for example want to recieve from S2 , in that > case all the G1.... Gn will recieve the data. > > am I right ?? > thanx From owner-malloc@catarina.usc.edu Fri Mar 16 14:51:07 2001 Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by ietf.org (8.9.1a/8.9.1a) with SMTP id OAA09465 for ; Fri, 16 Mar 2001 14:51:03 -0500 (EST) Received: (from majordom@localhost) by catarina.usc.edu (8.9.3/8.9.3) id LAA00179 for malloc-list; Fri, 16 Mar 2001 11:25:18 -0800 (PST) X-Authentication-Warning: catarina.usc.edu: majordom set sender to owner-malloc@catarina.usc.edu using -f Received: from rumi.usc.edu (rumi.usc.edu [128.125.51.41]) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id LAA00174 for ; Fri, 16 Mar 2001 11:25:17 -0800 (PST) Received: (from pavlin@localhost) by rumi.usc.edu (8.9.3/8.9.3) id LAA58106 for malloc@catarina.usc.edu; Fri, 16 Mar 2001 11:25:17 -0800 (PST) Received: from usc.edu (root@usc.edu [128.125.253.136] (may be forged)) by catarina.usc.edu (8.9.3/8.9.3) with ESMTP id BAA97514 for ; Fri, 16 Mar 2001 01:36:05 -0800 (PST) Received: from bells.cs.ucl.ac.uk (bells.cs.ucl.ac.uk [128.16.5.31]) by usc.edu (8.9.3.1/8.9.3/usc) with SMTP id BAA13375 for ; Fri, 16 Mar 2001 01:36:05 -0800 (PST) Received: from hocus.cs.ucl.ac.uk by bells.cs.ucl.ac.uk with local SMTP id ; Fri, 16 Mar 2001 09:28:11 +0000 To: Ali Boudani cc: ssm-interest@external.cisco.com, malloc@catarina.usc.edu, idmr@cs.ucl.ac.uk Subject: Re: hello In-reply-to: Your message of "Fri, 16 Mar 2001 09:42:13 +0100." <3AB1D1E5.A00CABCF@irisa.fr> Date: Fri, 16 Mar 2001 09:28:09 +0000 Message-ID: <24631.984734889@cs.ucl.ac.uk> From: Jon Crowcroft Sender: owner-malloc@catarina.usc.edu Precedence: bulk the problem it solves is the address _collision_ Problem - since all SSM G,s are specific to their S's, you don';t have to run a distributed algorithm or directory to do the allocation since there are no clash type problems. i.e. the malloc architecture is sidestepped. In message <3AB1D1E5.A00CABCF@irisa.fr>, Ali Boudani typed: >>I was wondering that SSM (before was the SImple Muticast or EXPRESS) use >>a channel like (S, G) and the drafts are saying that this is the >>solution to the address allocation problem because each group is >>represented with the souce address also. but why?? >>figure this : 2 groups (having the same address) want to recieve from >>the same source. the (simple multicast or EXPRESS or SSM) will consider >>them as the same group >>So in this case any (S, G) = (S, G1) .... (S, Gn) and there is no sense >>in the adress group of the recievers. >>at the same time if G2 (the recievers in the G2 but having the G >>multicast address group) for example want to recieve from S2 , in that >>case all the G1.... Gn will recieve the data. >> >>am I right ?? >>thanx >> cheers jon