GTP (GPRS Tunneling Protocol)
– It is an important tunneling protocol used in mobile packet switched networks.
– GTP is a set of IP based protocols to connect & carry PS (Packet Switched) data across 3GPP networks.
– GTP Header is based on UDP and is similar to TCP / UDP.
GTP Versions:
- There are three versions, v0, v1 & v2
- v0 & v2 works with both UDP & TCP
- v1 works with UDP only
- v2 introduced at the end of 2008, it will be used for EPC/LTE. v2 can fallback to V1 but not to V0.
- Echo Request & Response messages are common in all. Rest is all different.
GTP Sub Protocols:
1- GTP-C: used for signaling transfer between Packet Switch nodes e.g. setting up PDP contexts, mobility messages, etc.
2- GTP-U: used to carry data between Packet Switch nodes, e.g. carrying data separately for each PDP context.
3- GTP’ (GTP Prime): used to carry charging data to CGF (charging gateway function).
GTP based Interfaces:
Gn, Gp, S3, S4, S5, S8, S10, S11, S16, S101, and S1-U. For S1-C, GTP is not used, instead RANAP is used.
The end…