Re: DPC + OPC Routing
"Brian F. G. Bidulock" <[email protected]>
| Newsgroups | gmane.ietf.sigtran |
|---|---|
| Organization | http://www.openss7.org/ |
| Message-ID | <[email protected]> |
Cathy, Take a look at ANSI T1.112.4-2000/5.3.6.2(5) and 5.3.6.3(5). When SCCP Flow Control is used, MTP-STATUS (user part unavailable) will trigger local N-STATE primitives indicating "User-out-of-Service". Also ANSI T1.112.4-2000/5.3.6.7 and 5.3.6.8 N-PCSTATE will be locally broadcast indicating "SCCP inaccessible". Timer T(stat.info) is started or restarted in both cases and when it expires, N-STATE (User-in-service) and N-PCSTAT(SCCP accessible) will be locally broadcast. But also, see ANSI T1.112.4-2000/5.5.2 and 5.5.4 which specifically provide for SST (SSN=1) in response to MTP-STATUS (inaccessible or unknown). Again, as part of "Optional" SCCP Flow Control. Your information appears incorrect (or dated). --brian Newman, Catherine J wrote: (Tue, 10 Apr 2007 22:22:23) > Brian, > > ANSI SCCP does not support sending UPU for SCCP unavailability or > sending SSTs for SSN=1 (these procedures went in as a draft at one point > in the early 90's and then were deleted). (Note, ITU SCCP does support > UPU for SCCP unavailability / SSTs/SSAs for SSN=1) > > Instead, at an STP, a TFP/TFA regarding the alias PC should be sent (see > ANSI T1.111.4, Section 3.A and 3.B). There are no ANSI procedures, that > I am aware of, for handling SCCP unavailability at an end node. The > assumption was, I believe, that SCCP can't fail independently of MTP > with current end-node implementations. > > Cathy Newman > -- Brian F. G. Bidulock [email protected] http://www.openss7.org/