[cisco-voip] VG224 T.38

[voip at mrga.ch]

Hello all

we still have a problem with a VG224 Gateway. We connected it to our
Callmanager
4.2(3) and configured some ports (MGCP). When we want to make a call
from a
phone attached to the VG224 the destination phone rings and I can pick
up the
call. However I don't get a voice connection. The call terminates and I
get the
busy signal. After that I have to reboot the Port on the VG224.

Has anyone an idea??

Thanks Reto

It seems that the problem is related to T.38 (see packet capture below):

No.     Time        Source                Destination           Protocol Info
     34 7.574297                                                MGCP     MDCX
205 AALN/S2/1 at gw MGCP 0.1

Frame 34 (208 bytes on wire, 208 bytes captured)
Ethernet II, 
Internet Protocol, 
User Datagram Protocol, Src Port: 2427 (2427), Dst Port: 2427 (2427)
Media Gateway Control Protocol
    MDCX (ModifyConnection)
    Transaction ID: 205
    Endpoint: AALN/S2/1 at gw-test-fx1.hel.kko.ch
    Version: MGCP 0.1
    [The response to this request is in frame 36]
    Parameters
        CallId (C): A0000000010000b0000000F5
        ConnectionIdentifier (I): A
        RequestIdentifier (X): 9
        LocalConnectionOptions (L): L: p:20, a:PCMU, s:off, t:b8, fxr/fx:t38
            Packetization period (p): 20
            Codecs (a): PCMU
            Silence Suppression (s): off
            Type of Service (r): b8
            Unknown parameter:  fxr/fx:t38
        ConnectionMode (M): recvonly
        RequestedEvents (R): L/hu
        QuarantineHandling (Q): process,loop

		
No.     Time        Source                Destination           Protocol Info
     36 7.577209                                                MGCP     510 205
fx: setting cannot be supported

Frame 36 (82 bytes on wire, 82 bytes captured)
Ethernet II,
Internet Protocol, 
User Datagram Protocol, Src Port: 2427 (2427), Dst Port: 2427 (2427)
Media Gateway Control Protocol
    Response Code: The transaction could not be executed, because a protocol
error was detected. (510)
    Transaction ID: 205
    Response String: fx: setting cannot be supported
    [This is a response to a request in frame 34]
    [Time from request: 0.002912000 seconds]