asterisk users - May 2011 - Audiocodes MP-114 - modem dial not going through

I have an Audiocodes MP-114 and modem dial-out can not establish connection.

Snooping with Wireshark I get a lot of entries like this:

No.     Time        Source                Destination           Protocol Info
    2934 27.221559   10.0.0.110            10.0.0.109            RTP     
PT=ITU-T G.711 PCMU, SSRC=0x7D08611A, Seq=7662, Time=1805957855

Frame 2934: 214 bytes on wire (1712 bits), 214 bytes captured (1712 bits)
Ethernet II, Src: AudioCod_1d:ff:7f (00:90:8f:1d:ff:7f), Dst: AsustekC_de:a6:11
(00:1d:60:de:a6:11)
Internet Protocol, Src: 10.0.0.110 (10.0.0.110), Dst: 10.0.0.109 (10.0.0.109)
User Datagram Protocol, Src Port: x11 (6000), Dst Port: 12982 (12982)
Real-Time Transport Protocol

Is "G.711" what I should be using for modem connection?

-- 
Joseph