Re: RFC 4591 and RFC 4349
Javi Muñoz <javi <at> trajano.us.es>
2010-07-23 08:59:08 GMT
b) FRoPW (DLCI mode):
[ 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
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?
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