Please refer to the following reply from David Durham (I hope it's okay with David to be quoted without permission! ) to the same question a while back.
Regards,
--Probal.
> -----Original Message-----
> From: Dan Davidson [mailto:dan.davidson@commatch.com]
> Sent: Wednesday, July 24, 2002 3:58 PM
> To: rap@ops.ietf.org
> Subject: COPS : Clarifications
>
>
> Hi,
>
> In section 2.3 "Communication" of the COPS protocol
> (RFC 2748) the
> following
> sentences can be encountered:
>
> "The COPS protocol uses a single persistent TCP connection
> between the PEP
> and a remote PDP"
>
> a little later in the same section":
>
> "If a single PEP can support multiple client-types, it may
> send multiple
> Client-Open messages, each specifying a particular
> client-type to a PDP over
> one or more TCP
> connections".
>
> The question is: How many TCP connections are there ? A single one or
> multiples ?
>
> Thanks for the help,
> Best Regards,
> Dan
>
--- Begin Message ---Title: Question about COPS RFC (2748)
- To: Bhattacharjya Probal <probal.bhattacharjya@siemens.com>
- Subject: RE: Question about COPS RFC (2748)
- From: "Durham, David" <david.durham@intel.com>
- Date: Thu, 18 Apr 2002 23:52:21 +0800
Hi Probal,The COPS protocol using a single persistent connection between the PEP and remote PDP serving one or more client-types. Multiple client-types between the same PEP and PDP may share the same or establish multiple TCP connections (no more than one per client type, however). There is an efficiency gain if they all share the same TCP connection, but this is not a MUST.I agree the RFC is not very clear on this. The answer is one or more TCP connections, no more than one per client-type, with one being the preferred arrangement.-Dave--- End Message --------Original Message-----
From: Bhattacharjya Probal [mailto:probal.bhattacharjya@siemens.com]
Sent: Wednesday, April 17, 2002 6:15 PM
To: David.Durham@intel.com
Subject: Question about COPS RFC (2748)Dear Sir,
I have a possibly silly question about the COPS RFC (RFC 2748) and would like to have your clarification as the editor of the RFC. In section 2.3 called "Communication" the very first sentence asserts that
"The COPS protocol uses a SINGLE persistent TCP connection between the PEP and a remote PDP".
And then in the second paragraph, the first sentence (which spans three lines) says
"If a single PEP can support multiple client-types, it may send multiple Client-Open messages, each specifying a particular client-type to a PDP over one or MORE TCP connections"
[I have EMPHASISED the parts I want to draw your attention to!]
My question is if according ot the former sentence there could only be a "SINGLE" TCP connection between a PEP and a PDP, then how is it according to the latter sentence that a PEP may send multiple messages to a PDP over possible "MORE than one" TCP connections?
Is it then possible to have "more than one" TCP connection between a PEP and a PDP? In that case the former sentence is not correct in asserting that there could only be a "single" TCP connection between them!!
Please clarify.
Thanks,
--Probal.---------------------------------------------------------
Probal K. Bhattacharjya
Siemens Pte Ltd