Chapter 4 FortiOS Carrier : ­­­­Overview of FortiOS Carrier features : GTP basic concepts : Transport : GTPv2
  
GTPv2
GTPv2, defined in 3GPP TS 29.274, is dramatically differnet from GTPv1, defined in 3GPP TS 29.060. Where in GTPv1 the tunnel is between the SGSN and the GGSN, in GTPv2 The SGSN is between the MME and the LTE Serving Gateway (S-GW), beyond which is the PDN gateway (P-GW). Even tunnel management messages have changed significantly.
Figure 145: Network diagram for GTPv2
 
Table 34: Device roles on a GTPv2 network
Device role
Neighboring Devices
Interfaces used
Protocols used
Mobile Users
Mobile Stations (MS)
Radio Access Technology (RAT)
--
GTPv1 Mobile Stations (MS)
Mobile Users, SGSN
Gb
IP, Frame Relay
GTPv2 Mobile Stations (MS)
Mobile Users, MME
???
IP, Frame Relay
SGSN (local)
GTPv1 MS, SGSN, S-GW
???
IP, Frame Relay, GTPv1, GTP’
S-GW
SGSN, MME, P-GW
???
IP, GTPv2, GTP’
P-GW
S-GW, Internet, other external services
???
IP, GTPv2