Re: M2PA BSN dis-ordering
"Brian F. G. Bidulock" <[email protected]>
| Newsgroups | gmane.ietf.sigtran |
|---|---|
| Organization | http://www.openss7.org/ |
| Message-ID | <[email protected]> |
Bibhuti, If you are following Q.703, the handling is per that standard. One isolated abnormal BSN is ignored, but two consecutive abnormal BSNs cause the link to be put out of service. So at the end of your sequence B sends FSN=14 BSN=4 and FSN=15 BSN=5, however, if another abnormal BSN follows, OUT-OF-SERVICE is sent from B. You can see this in test cases 3.8.10 and 3.8.11 in draft-bidulock-sigtran-m2pa-test-06.txt and in Q.781/Test 8.10 and Q.781/Test 8.11. T7 is not impacted by the abnormal BSN per the Q.703 SDLs because the abnormal BSN does not negatively or positively acknowledge any message. But this is defined by SS7 MTP2 and not altered by M2PA: therefore, it is of some advantage to learn how a traditional SS7 link works before working with M2PA. --brian Bibhuti Bhusan Tosh wrote: (Fri, 26 May 2006 11:09:32) > > Hi All > > > > Kindly consider the following call flow and suggest me for the valid > FSN and BSN values. > > > > A B > ---------------------------- ---------------------------- > > > > MTP3 M2PA SCTP SCTP M2PA MTP3 > ---- ---- ---- ---- ---- ---- > > > > User Data FSN=1 BSN=10 . . > ------------------------------------> . . > User Data FSN=2 BSN=10 . . > ------------------------------------> . . > User Data FSN=3 BSN=10 . . . . > ------------------------------------> . . > User Data FSN=11 BSN=3 . . > <------------------------------------ . . . . > User Data FSN=12 BSN=3 . . > <------------------------------------ . . . . > User Data FSN=13 BSN=3 . . > > <------------------------------------ . . . . > User Data FSN=4 BSN=12 . . . . > ------------------------------------> . . . . > User Data FSN=? BSN=? . . > <------------------------------------ . . . . > User Data FSN=5 BSN=11 . . . . > ------------------------------------> . . . . > User Data FSN=? BSN=? . . > <------------------------------------ . . . . > > Is there any impact of T7 timer expiry? > > > > Regards, > > Bibhuti > _______________________________________________ > Sigtran mailing list > [email protected] > https://www1.ietf.org/mailman/listinfo/sigtran -- Brian F. G. Bidulock [email protected] http://www.openss7.org/