Re: RFC 4591 and RFC 4349

Hi Ignacio,

>> b) FRoPW (DLCI mode):
>>
>>            C1                            C2
>>   [ FR A ]----[ LCCE 1 ]------[ LCCE 2 ]----[ FR B ]
>>
>>                <------ L2TP FRoPW ---->
>>          <---->                         <---->
>>         FR traffic                   FR traffic
>>
>> ...
>> In this mode, the L2TP cloud behaves as if it were a FR switch.
>>
>> ===
>>      
>> b) FRPWs: according with your explanation, I would understand the next one:
>>
>>                                            ¿ ?
>>                                             |
>>                                             |
>>                                            \ /
>> DTE - PE/DCE<== FRPW ==>  PE/DCE - ¿DTE?<== Data Network ==>  DCE - DTE
>>   <Q.933>                      <Q.933>                           <Q.933>
>>   <-------------------------- FR VC -------------------------------->
>>   <DLCI_1>  [DLCI switching]<DLCI_2>      [ DLCI switching ]<DLCI_3>
>>            [DLCI_1 =>  DLCI_2]            [DLCI_2 =>  DLCI_3]
>>
>>     However, it would not be possible, due to the access nodes to the data network must be DCEs.
>>      
> I imagine that if someone wanted to use FR over an L2TP PW,
> the LCCEs (or the devices feeding into the LCCEs) would have
> to be DCE or DTE as needed. There are many devices out there
> that can be configured as either DCE or DTE so this shouldn't
> really be a problem.
>    

I need to detail this scenario for an specific application of the FRPWs 
(to ISDNs).

According to the working of the FRPWs, I think that the DTE/DCE 
funcionality of each CEs and PEs would be:

CE1(DTE) - PE1(DCE)<== FRPW(DLCI switching) ==>  PE2(DCE) - CE2(DTE)


However, when I consider a back to back comunication between tww FR 
terminals, that behaviour is not coherent with the classical FR working:

CE1(DTE,FR terminal) - PE1(DCE)<=FRPW=>  PE2(*DCE*) - CE2(*DTE*)<=Data Network=>  DCE - DTE (FR terminal)


 From the point of view of the "Data network", it would be:

CE1(DTE,FR terminal) - PE1(DCE)<=FRPW=>  PE2(*DTE*) - CE2(*DCE*)<=Data Network=>  DCE - DTE (FR terminal)


but it would not coincide with the "DLCI swithing" working of the FRPWs.


Could you help me to assign the DTE or DCE behaviour of each equipment 
in this back-to-back communication?


Thanks,

Javi

_______________________________________________
L2tpext mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/l2tpext