[j-nsp] l2circuit for frame relay

[sthaug at nethelp.no]

> We are trying to migrate a frame relay network onto our mpls network,  
> based on juniper M10i routers.
> We are using frame-relay-ccc encapsulation and l2circuit configuration.
> The problem is that we are unable to configure dlci values below 512.
> We get the following error when trying to configure units with dlci  
> below 512:
> 
> CCC or TCC on this interface must have a DLCI >= 512
> 
> Is this a known limitation?
> Can this be worked around somehow?

Probably the same limitation that you have on Ethernet interfaces
when you try to mix L2 and L3 VLAN subinterfaces on the same physical
interface.

You may be able to get it to work for DLCIs less than 512 with one of
the following encapsulations on the physical interface:

- extended-frame-relay-ccc / extended-frame-relay-tcc - this probably
means that you will be able to use the physical interface for L2 only
(CCC, TCC etc). You won't be able to have L3 (e.g. IP) subinterfaces
on the same physical interface.

- flexible-frame-relay - works only on IQ PICs but should be able to
handle any mix of DLCIs and L2 / L3 subinterfaces.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no