GTP'

GTP' (GTP prime) is an based protocol used within GSM and UMTS networks. It can be used with or . GTP' uses the same message structure as (GTP-C, GTP-U), but it is largely a separate protocol. GTP' uses registered UDP/TCP port 3386.

GTP' can be used for carrying charging data from the "Charging Data Function" (CDF) of the GSM or UMTS network to the "Charging Gateway Function" (CGF). In most cases, this should mean from many individual network elements such as the GGSNs to a centralised computer which then delivers the charging data more conveniently to the network operator's billing center.

GTP' is used on the Ga interface within the 3GPP GPRS Core Network definition.

GTP' reuses aspects of GTP although to quote 3GPP TS 32.295 "only the signalling plane of GTP is partly reused". GTP' defines a different header, additional messages, field values, as well as a synchronisation protocol to avoid losing or duplicating CDRs on CGF or SGSN/GGSN failure. Transferred CDRs, if following 3GPP standards, are encoded in ASN.1.

GTP' v1 and v2 headers contain the following fields

GTP' uses the GTP Version Not Supported, Echo Request and Echo Response messages unchanged, but adds the following messages

The Node Alive messages are used to advise other network components that a node has started service. The request is sent from the node starting and so provides a faster method to re-enable service than polling using Echo Request/Response does. This message can also be used to advise of other nodes coming back into service, and (in GTP' version 2) to advise of the IPv6 address of the CGF.

The Redirection messages are used to:

In either case the CDFs are given more information about an impending or immediate failure than would be the case if the CDF was polling using Echo Request messages.

This message contains details about the cause, and optionally address(es) of an alternate CGF.

The Data Record Transfer messages are used to reliably transport CDRs from the point of generation (SGSN/GGSN) to non-volatile storage in the CGF.

...
Wikipedia