Preferred Codec?

i want to force asterisk to use the G.711 ulaw codec first and formost. My polycom phones (don’t get me started) use G711. I use the “disallow=all” and then the “allow=uLaw,G.711” commands in the general section, as instructed, but when a call is made i get the error, "Cannot allow known format ‘G.711’ " any clues? also in the CLI, I get the debug message: “can_sip.c:2772 process_sdp:No compatible codecs”.
Using PRI/T1 if that matters any.
Thanks in advance

all you need is “allow=ulaw”. no G.711 in there.