jeffmac - here is a snippet of the log file. FYI, the ip address is not the actual one shown in the log file. Thanks in advance for your help.
Also Allow Anonymous Inbound SIP Calls = No
[2014-07-24 21:00:48] VERBOSE[12900] netsock2.c: == Using SIP RTP TOS bits 184
[2014-07-24 21:00:48] VERBOSE[12900] netsock2.c: == Using SIP RTP CoS mark 5
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [5011972592863739@from-sip-external:1] NoOp("SIP/87.432.456.22-0000090a", "Received incoming SIP connection from unknown peer to 5011972592863739") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [5011972592863739@from-sip-external:2] Set("SIP/87.432.456.22-0000090a", "DID=5011972592863739") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [5011972592863739@from-sip-external:3] Goto("SIP/87.432.456.22-0000090a", "s,1") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Goto (from-sip-external,s,1)
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [s@from-sip-external:1] GotoIf("SIP/87.432.456.22-0000090a", "0?from-trunk,5011972592863739,1") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [s@from-sip-external:2] Set("SIP/87.432.456.22-0000090a", "TIMEOUT(absolute)=15") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] func_timeout.c: Channel will hangup at 2014-07-24 21:01:03.452 EDT.
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [s@from-sip-external:3] Answer("SIP/87.432.456.22-0000090a", "") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: == Spawn extension (from-sip-external, s, 3) exited non-zero on 'SIP/87.432.456.22-0000090a'
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [h@from-sip-external:1] NoOp("SIP/87.432.456.22-0000090a", "Hangup") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [h@from-sip-external:2] Set("SIP/87.432.456.22-0000090a", "DID=s") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [h@from-sip-external:3] Goto("SIP/87.432.456.22-0000090a", "s,1") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Goto (from-sip-external,s,1)
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [s@from-sip-external:1] GotoIf("SIP/87.432.456.22-0000090a", "0?from-trunk,s,1") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [s@from-sip-external:2] Set("SIP/87.432.456.22-0000090a", "TIMEOUT(absolute)=15") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] func_timeout.c: Channel will hangup at 2014-07-24 21:01:03.633 EDT.
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: -- Executing [s@from-sip-external:3] Answer("SIP/87.432.456.22-0000090a", "") in new stack
[2014-07-24 21:00:48] VERBOSE[13667] pbx.c: == Spawn extension (from-sip-external, s, 3) exited non-zero on 'SIP/87.432.456.22-0000090a'
[2014-07-24 21:01:03] VERBOSE[13690] manager.c: == Manager 'aastra-xml' logged on from 127.0.0.1