Facilitating uninterrupted transmission of internet protocol (IP) transmissions during endpoint changes is disclosed. When an IP transmission is received at a first relay port or a second relay port, a call record having the first relay port identifier or the second relay port identifier matching a destination port identifier in the IP transmission is located. When the destination port identifier matches the first relay port identifier of the record, a source IP address identifier and a source port identifier from the IP transmission are set as a first entity IP address identifier and first entity port identifier, respectively, of the record when the first entity IP address identifier and first entity port identifier do not match the source IP address identifier and source port identifier respectively and a received IP session identifier in the IP transmission matches the first entity session identifier. A similar procedure is followed to set a second entity IP address identifier and port identifier.