Pseudo-wires: uni-directional o bi-directional?

A pseudo-wire is: uni-directional o bi-directional?

I thought that it was necessary to set up two symmetrical TDMoMPLS 
pseudo-wires (one for each direction) for emulating a bidirectional TDM 
circuit o HDLC/FR link.

However, I found confusing references:

RFC 4591 (L2TPv3 FRoPW), clause 5
There is a one-to-one mapping between a Frame Relay PVC and *an
FRPW, supporting bi-directional **transport *of variable length frames.


RFC 3985 (PWE3 Architecture)
7.3.1.  Pseudo Wire Up/Down Notification
    If a native service requires bi-directional connectivity, the
    corresponding emulated service can only be signaled as being up when
    the *PW* and PSN tunnels (if used), are *functional in both directions*.


RFC 5087 (TDMoIP PWs), clause 3
Since TDM is inherently bidirectional, the *association of two PWs in 
opposite directions is required*


RFC 5087 (TDMoIP PWs), clause 6
Since TDM *PWs are inherently bidirectional*


RFC 4591 (PWE3 Requirements), clause 5.1
If a native circuit is bi-directional, the corresponding emulated
circuit can be signaled "Up" only when the associated PW and PSN
tunnels *in both directions are functional*.


Javi

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