[Serusers] bearer capability not implemented

I am using a Cisco ATA 186 and a Cisco AS5350 in conjunction with a SER SIP server. When I try to place calls from the ATA to the PSTN, I am getting the following error. Is there a command that I can issue on the Gateway to provide more information for debug? Thanks, Stephen Total call-legs: 2 1284 : 46480131hs.94 +-1 +0 pid:1 Originate 13125551212 dur 00:00:00 tx:0/0 rx:0/0 41 (bearer capability not implemented) Telephony 3/0:D (180): tx:0/0/0ms None noise:0dBm acom:0dBm 1284 : 46480129hs.95 +-1 +3 pid:700 Answer 256 dur 00:00:00 tx:0/0 rx:0/0 41 (bearer capability not implemented) IP 209.242.10.153:16384 rtt:0ms pl:0/0ms lost:0/0/0 delay:0/0/0ms g711ulaw U 66.155.138.5:5060 -> 209.242.10.153:5060 SIP/2.0 100 Trying..Via: SIP/2.0/UDP 209.242.10.153;branch=z9hG4bK7b35.fb17 329.0,SIP/2.0/UDP 216.145.234.84:5060..From: <sip:256@209.242.10.153;user=p hone>;tag=741484739..To: <sip:18475551212@209.242.10.153;user=phone>;tag=1B C0FF10-3C3..Date: Thu, 06 Jan 2000 09:20:30 GMT..Call-ID: 1667923238(a)216.14 5.234.84..Server: Cisco-SIPGateway/IOS-12.x..CSeq: 1 INVITE..Content-Length : 0.... # U 66.155.138.5:5060 -> 209.242.10.153:5060 SIP/2.0 501 Not Implemented..Via: SIP/2.0/UDP 209.242.10.153;branch=z9hG4bK 7b35.fb17329.0,SIP/2.0/UDP 216.145.234.84:5060..From: <sip:256@209.242.10.1 53;user=phone>;tag=741484739..To: <sip:18475551212@209.242.10.153;user=phon e>;tag=1BC0FF10-3C3..Date: Thu, 06 Jan 2000 09:20:30 GMT..Call-ID: 16679232 38@216.145.234.84..Server: Cisco-SIPGateway/IOS-12.x..CSeq: 1 INVITE..Conte nt-Length: 0....