I just setup an SBC 10.2 with SIP trunks to AT&T, IPO was already in place as version 11.1.
When making an outbound call, the sip header is adding a "L" in the "TO" field, for example To: <sip:15555551212L@10.21.1.10>
I cannot for the life of me figure out where this "L" is coming from, it is...