Yes. Create a SIP trunk on the 6310 pointing to the IP of the TA924. Add a voice grouped-trunk referencing the new trunk, and on it apply an accept pattern with a cost higher than that going over the trunk to the remote PBX. This can be a $ for accept all or you may want to limit it to exclude extensions in order to prevent confusion.
If the PBX expects a leading "9" for outside, use match-substitute in the trunk configuration to strip the "9" so that users don't need to dial anything differently. For example:
match dnis 9-1-NXX-NXX-XXXX substitute 1-NXX-NXX-XXXX
match dnis 9-NXX-XXXX substitute NXX-XXXX
match dnis 9-N11 substitute N11
Great! Thanks for the assist.
Service Support Representative
37 Years of Excellence !
212-780-9680 x.137 Voice
“It is the word which speaks boldly of your intention and the action which speaks louder than words”
1201 Broadway, Suite 1010
New York, NY 10001