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GTP' (GTP prime) is an IP based protocol used within GSM and UMTS networks. It can be used with UDP or TCP. GTP' uses the same message structure as GTP (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".〔3GPP TS 32.295〕 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. ==Header== GTP' v1 and v2 headers contain the following fields ; Version : The first header field in a GTP' packet is the 3-bit version field. For GTP' v2, this has a value of 2 (hence the name GTP' v2). ; Protocol Type (PT) : a 1-bit value that differentiates GTP' (value 0) from GTP (value 1). ; Reserved: a 3-bit reserved field (must be 1's). ; Header Length (Hdr len): a 1-bit value that for GTP' version 0 indicates if using a 20 byte header (value 0) (as per GTP) or this 6 byte header. This bit must be unset (value 0) for subsequent GTP' versions and in these does not indicate the header length as this must always be 6 bytes. ; Type: An 8-bit field that states the packet type. ; Length: A 16-bit field that states the length of the packet being encapsulated by GTP' (not including the GTP' header itself). ; Sequence Number: A 16-bit field that uniquely identifies this packet and allows detection of loss or duplication 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「GTP'」の詳細全文を読む スポンサード リンク
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