[c-nsp] L2/L3 Failover Design

[redphive]

Hello List,

I have two sites which are connected via two microwave radios in parallel,
one operating at 155Mb/s (OC3 with Gbe Interfaces) and one at 100Mb/s.  We
have three types of traffic, L3 Residential Internet on the 155Mb/s link,
enterprise and management traffic including VoIP, and multiple L2 commercial
customer TLS circuits on the 100Mb/s link.  The combined traffic of all
types is about 100Mb/s.

We are trying to determine a way that would provide some fail over
protection in both directions should one of the radio links fail.  We have
looked at pvst+ and rapid-pvst+ on 2970s but either through poor
configuration or shortcomings of the technology were not satisfied with the
results. (Note I have assumed these duties in the extended absence of who
was working on this previously)

We would like to preserve some of the bandwidth on the 100Mb/s link for VoIP
traffic should the 155Mb/s link fail, so QoS would be a concern, but isn't
mandatory.

Has anyone run into a similar scenario, or could provide some insight as to
how this would best be handled?

Thanks in advance,

Aaron