Cell Relay Archive

["Michael D. Todd" <toddmd@aur.alcatel.com>]

Jae young Park wrote:
> 
> Hi all,
> I have read some document about the "ATM Intenetworking".
> and find out some question,
> "In UNI3.0/3.1, the traffic parameters and requested QoS for a connection
> cannot be negotiated at set-up, or changed over the lifetime of connection.
> UNI 4.0 will be support that."
> if it is true, UNI3.0 cannot support rt-VBR or CBR connction?
> if not, have I missed, may be it is, anything?
> Please inform me that.



I'm pretty sure the followig applies to UNI 3.0, but 
I can say for sure that UNI 3.1 does support signaling for
VBR-rt/nrt & CBR. The problem with CBR & VBR-rt is the 
lack of individual QoS for each call (supported in Uni 4.0, 
in Uni3.1 you only get a QoS per class -- see Uni 3.1/appendix F.)

Your confusion about VBR probably has to do with the 
dynamic nature of the traffic contract -- PCR, MBS, SCR -- 
while the atm cell flow may dynamically change, the 
statistical description in the traffic contract 
accurately describes the traffic flow for the life 
of the call. 

The negotiation in UNI4.0 applies only to the call 
setup -- the traffic contract must be observed by the 
endpoints after the call is CONNECT'ed. 


> 
> <><><><><><><><><><><><><><>
> Jae young Park
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> Choice of Glory~

-- 
Mike

Michael Todd; Alcatel USA; Raleigh, NC USA