The IMG supports the passing of the ‘+’ sign from the incoming SIP side to the outgoing SIP side, or the removal of the "+" if you do not want to pass it through. This process is only applied to INVITE.
This feature is enabled in the SIP Profile with the Append (+) for Headers and Remove (+) for Headers fields.
This feature can be applied to the following headers in the INVITE:
R_URI
FROM
TO
P_ASSERTED
P_PREFERRED
REMOTE_PARTY_ID
Note: The Contact header is not put into the bit mask, but ‘+’ is supported in the Contact header if it is included in the incoming Contact.
Note: The ‘+’ is not supported for routing or translation; only a simple pass through.