GTP: use direct call instead of ITTI
Using ITTI calls for user plane implies (1) a memory allocation, (2) mutexes, and (3) queueing messages for each user plane packet, which is heavy. Use a direct API call instead to reduce overhead.
Using ITTI calls for user plane implies (1) a memory allocation, (2) mutexes, and (3) queueing messages for each user plane packet, which is heavy. Use a direct API call instead to reduce overhead.