Re: RFC 4591 and RFC 4349: DLCI at egress LCCE

Javi wrote:
> Ignacio,
> 
> Thanks for the diagram.
> 
> The doubt is about FRoPW:

Ok, this is a different question. You were asking earlier about FR in 
"port mode" which is HDLCoPW, not FRoPW.


For FRoPW, the correct drawing is this:

>            C1                            C2
>   [ FR A ]----[ LCCE 1 ]------[ LCCE 2 ]----[ FR B ]
> 
>               <------ L2TP FRoPW ---->
>           <---->                       <---->
>         FR traffic                   FR traffic

where "FR traffic" here means Q933 exchanges. The actual data traffic
for each PVC is obviously transported end to end (ie, FR A to FR B
and viceversa).


  >  From the CE point of view, FR link is finished by remote system?:

Yes, because the DLCIs in _this_ mode have local significance.
In other words, Q933 exchanges happen between "FR A" and "LCCE 1" in
one end and between "FR B" and "LCCE 2" on the other end.

In this mode, the L2TP cloud behaves as if it were a FR switch,
if that makes it easier to understand.

-Ignacio