RE: SE-IPSP definition
"Tolga Asveren" <[email protected]>
| Newsgroups | gmane.ietf.sigtran |
|---|---|
| Message-ID | <[email protected]> |
Brian, (To prevent mailing list pollution my last message on this subtopic -maybe not on this thread- ) > -----Original Message----- > From: Brian F. G. Bidulock [mailto:[email protected]] > Sent: Thursday, November 10, 2005 8:55 AM > To: Tolga Asveren > Cc: [email protected] > Subject: Re: [Sigtran] SE-IPSP definition > > > Tolga, > > Tolga Asveren wrote: > (Thu, 10 Nov 2005 08:22:32) > > Brian, > > > > [..snip..] > > > - To have a single exchange of messages it is a necessary > that one side > > > behave like an ASP (messages and state machines) and the > other behave > > > like an SGP (messages and state machines). > > [TOLGA]Wrong. Take a look to Figure 3. IPSP can send and > receive ASPAC/ASPIA > > messages. As an example -just showing ASPAC messages- > > > > SE-IPSP1 SE-IPSP2 > > | | > > |-------ASPAC------------->| > > | | > > |<-----ASPAC-ACK-----------| > > | | > > | AS is active at both | > > | sides | > > | | > > |<-------ASPIA-------------| > > | | > > |------ASPIA-ACK---------->| > > | | > > | AS is inactive | > > | at both sides | > > | | > > > > The above is a valid message sequence. Neither ASP nor SGP can > support the > > above message exchange. Thinking that an SE-IPSP behaves as ASP and the > > other one as SGP for the whole set of message exchanges is > wrong. I singled > > out this issue because this is the key of the confusion. > Basically, an IPSP > > is an IPSPS neither ASP not a SGP. > > This message exchange is not required to be supported. [TOLGA]Sorry but you are totally wrong. This is very well supported by SE-IPSP state machine. > > The following two other possibilities are just as valid: > > SE-IPSP1 SE-IPSP2 > | | > |-------ASPAC------------->| > | | > |<-----ASPAC-ACK-----------| > | | > | AS is active at both | > | sides | > | | > |<-------ASPIA-------------| > | | > |-ERR[Unexpected Message]->| > | | [TOLGA] This is supported from M3UA point of view but means that your SE-IPSP1 is either not an SE-IPSP or a broken one, because it does not support IPSP state machine as defined by the specifications. > > > SE-IPSP1 SE-IPSP2 > | | > |-------ASPAC------------->| > | | > |<-----ASPAC-ACK-----------| > | | > | AS is active at both | > | sides | > | | > |<-------ASPIA-ACK---------| > | | > |-------ASPAC------------->| > | | > |<---ERR[Mgmt. Blocking]---| > | | [TOLGA]Hmmm, I am not sure about this. IMO no need to support this -because SE-IPSP2 can send ASPIA instead of ASPIA-ACK- but OTOH this has nothing to do with our discussion. > > --brian > > -- > Brian F. G. Bidulock > [email protected] > http://www.openss7.org/ >