Open Issues with ATM-over-PSN
The ATM service draft does not provide a complete solution
Control Plane:
- ATM service draft only addresses the forwarding plane
- PWE3 Control plane could be provided by draft-ietf-pwe3-control-protocol
- This does not interwork well with ATM control plane (PNNI) since this requires signalling of traffic parameters, class of service, bandwidth reservation for PW
- ATM Forum is in advanced development of a spec extending PNNI to control pseudo-wires
Quality of Service:
- ATM has very strict QoS requirement that need to be supported by PSN to respect current ATM SLAs
Management:
- ATM has many OAM applications which may need to interwork with those in the PSN
PWE3 does not aim to solve all of these!