Re: SE-IPSP definition
"Brian F. G. Bidulock" <[email protected]>
| Newsgroups | gmane.ietf.sigtran |
|---|---|
| Organization | http://www.openss7.org/ |
| Message-ID | <[email protected]> |
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.
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]->|
| |
SE-IPSP1 SE-IPSP2
| |
|-------ASPAC------------->|
| |
|<-----ASPAC-ACK-----------|
| |
| AS is active at both |
| sides |
| |
|<-------ASPIA-ACK---------|
| |
|-------ASPAC------------->|
| |
|<---ERR[Mgmt. Blocking]---|
| |
--brian
--
Brian F. G. Bidulock
[email protected]
http://www.openss7.org/