Cell Relay Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Re: CR:query on PNNI topology database update
agupta wrote: > > Distribution: world > > Hi, > > I have some doubt about routing topology update in case of Call failure. > > In case a call is rejected by the enduser, PNNI specs says that > alternate routing will not be attempted and call should be released > straight away. Now in this case how the PNNI routing topology database > is updated (i.e. capacity allocated during call setup is freed)? > Is it by exchanging PTSEs (flooding mechnism)? That's just the same as with every change of the link state. If the change is significant (relative change to the last value flooded is larger than given in the proportional multiplier), then the new value is flooded. BTW: There are two possible strategies on when to reserve capacity: You could - either allocate resources for a link when the SETUP is received - or allocate resources when the CONNECT message is received. To be on the safe side you should normally follow the first approach for resource allocation. In this case, you also have to release resources, when the connection will fail at a later stage. For flooding link states you could also use the second way. Flooded link states may always be inaccurate (at least in the order given by the proportional multiplier). So it does not matter, when for the time between the SETUP and the CONNECT (or RELEASE) the link state information does not exactrly reflect the link reservations. > Thanks in advance! > > Anil -- Martin Winter ------------------------------------------------------ Siemens AG Voice: +49 89 722-63718 OEN ME 32 Fax: +49 89 722-26877 Hofmannstr. 51 Mail: Martin.Winter@oen.siemens.de 81359 Muenchen Germany |
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