GSMPv3 and L2C

DSL Forum is working on a protocol for interaction between =
access-nodes(e.g DSLAMs) and BRAS devices (controllers in gsmp-speak) in =
an atm or ethernet based access networks.
Avri had posted on the list the DSL forum draft on this work (L2CP - L2 =
control protocol). The idea is to extend GSMPv3 to implement =
requirements of the L2 control protocol.=20
In going through the current GSMP RFCs, and the DSL forum document a =
couple of observations :

1. GSMP RFCs suggests that switch is the passive entity with respect to =
tcp connectivity. The controller initiates the TCP connection. In =
certain cases (e.g in L2C it makes sense to let=20
    the controller be passive w.r.t TCP connection, and let the =
access-node(s) initiate TCP connection).  Does it make sense for the =
GSMP spec to not require that controller initiate the tcp connection=20
   but keep it be open such that this behaviour can be config driven on =
the devices involved. The applicability document can capture specifics =
of different applications.
  =20
2. The adjacency protocol in GSMP has version number negotiation =
support. Was there any discussion when GSMP was being designed to take a =
more general approach to capability negotiation=20
    between the swtich and controller (e.g  by including capability TLVs =
in adjacency protocol messages) ? This helps extensibility in general.

Will appreciate feedback (including general discussion on extending =
GSMPv3 to implement L2C as specified in the DSL forum doc)...

Thanks
-Sanjay