Re: single/double exchange mode doubt
"Ankit Kumar Sharma" <[email protected]>
| Newsgroups | gmane.ietf.sigtran |
|---|---|
| Message-ID | <[email protected]> |
On 7/10/07, Brian F. G. Bidulock <[email protected]> wrote: > > Ankit, > > Ankit Kumar Sharma wrote: (Thu, > 05 Jul 2007 15:43:53) > > > > Hi all, > > > I have a doubt over single/double exchange mode. When we say > > single/double exchange mode then do we mean: > > a) it is a property of ASP. For all ASs served by this ASP, my > mode > > would be either single or double exchange, but not both. > > ASPs do not do single or double exchanges: IPSPs do. Agreed. Thanks for pointing out this mistake... > b) it is a property of AS. For one AS, an ASP could behave as in > > single exchange and for other it could behave as a double exchange. > > No. If we look at the IPSP SE/DE communication in sections 5.6.1 and 5.6.2 of RFC 4666, behavior of IPSP SE and DE is almost same till ASPSM messages are exchanged. Now, when we exchange ASPTM message(ASPAC), then there is a distinction between SE and DE exchange model. If I am not wrong then ASPTM messages are more specific to AS and hence we could say that SE/DE is a property of AS. Peer could be configured in such a way that after recieving ASP-ACTIVE with RC=x, it should make its local IPSP active with RC=x(SE mode), whereas if it receives RC=y in ASPAC then it just acknowledges the ASPAC message, as in DE mode. > Please look at the example below: > > ---------- ------------ > > |ASP 1|----------------------|ASP A | > > ---------- ----------- > > ASP 1 is serving AS 1 with routing context 1. ASP A is serving AS > A, > > with routing context 1. This configuration is running fine in > single > > exchange mode. > > Now, I want to add one more AS at ASP 1, say AS 2. Routing context > of > > this AS would be 2 and I want to run it in double exchange mode. > Do > > someone see any discrepancy in this configuration? > > ASPs do not communicate directly with each other in this fashion: IPSPs > do. Why do we send ASP-Active ,when running in IPSP mode, when we do not have ANY ASP at both ends?...we should send IPSP-Active...:-) The RFCs state that both IPSPs must operate in the same mode for all > messages. --brian > > > -- > Brian F. G. Bidulock > [email protected] > http://www.openss7.org/ Cheers, Ankit _______________________________________________ Sigtran mailing list [email protected] https://www1.ietf.org/mailman/listinfo/sigtran