The MPLS WG Archive

[David Charlap <david.charlap@marconi.com>]

Curtis Villamizar wrote:
> Kainia Cloutier writes:
>>
>> I'm currently in London, attending the MPLS Next Generation
>> Networking conference. I came to this conference with one objective:
>> finding out how to map an LSP to specific ATM switching hardware,
>> while using RSVP-TE. For the last several weeks, I read RFCs 2205,
>> 2210, 2212 and several IETF drafts and still couldn't find one paper
>> describing "an edge LSR, sending a path message with these parameters
>> set in the ADSPEC and FLOWSPEC object, will receive, from a
>> downstream node, an ATM CBR label mapping". (and so on and so forth
>> for RT-VBR, NRT-VBR, UBR label mappings).

Strangely enough, I haven't been able to locate an RFC or draft that
maps IntServ-style QoS specs onto ATM-style.  Which does strike me as
odd.

> QoS is supported with the services defined in the diff-serv WG and to
> the extent that diff-serv services such as EF, AF, etc can be mapped
> onto ATM you have compatibility with the legacy ATM devices.

It is also supported by signalling QoS vis IntServ objects.  Each ATM
switch that supports IntServ will have to reserve according to these
parameters.  If the hardware can only make reservations using ATM-style
parameters, then some form of mapping will be needed.

Although there are a number of RFCs that mention RSVP and ATM together
(2379, 2380, 2381 and 2381), a quick scan of their content didn't reveal
any standard formulae for converting one style of resource
representation to the other.

-- David