Re: proposed charter 5 priority levels
Fred Baker <[email protected]> Wed, 27 Sep 2006 16:53:44 -0700
| Newsgroups | gmane.ietf.ieprep |
|---|---|
| Message-ID | <[email protected]> |
On Sep 27, 2006, at 3:39 PM, John Rosenberg wrote: > It's been mentioned that both RSVP and NSIS can carry both SIp > priority and DSCP. > > For the uninitiated (e.g. me!) would the use of either of these > protocols be used in a scenario where: > > 1) an endpoint sent an INVITE to a call controller withtout RPH, > but with "dialed digits" that request a DSN precedence level (e.g. > Flash); > > 2) the call controller validated that the requested precedence > level is authorized; > > 3) and the call controller then needs to inform the endpoint what > specific DSCP value (e.g. 41) to put in the bearer packets that the > EP generates, which value is based on a provisioned mapping > resident in the call controller between dsn precedence levels and > DSCP values. This is all stated in layer seven words and doesn't much address layer 3 issues. The thing is that the layer 7 issues are different than teh layer 3 issues, and both have to be addressed. Yes, I think (as described in RFC 3312), the two would be used together. I have some slides at ftp://ftpeng.cisco.com/fred/new-ef if you're interested to peruse them. The big differences between RSVP and NSIS, taken from 33,000 feet, are that RSVP works for multicast while NSIS doesn't, NSIS provides a firewall traversal mechanism that RSVP doesn't, and RSVP has this all spelled out in consensus standards and mostly implemented in vendor product that has been proven interoperable, while NSIS is quite a bit further behind on the road map.