GTP Cause Codes

Dalam GTP request, cause value menunjukkan alasan request tersebut. Cause value tersebut akan dimasukkan dalam GTP request message.

Dalam GTP response, cause value menunjukkan acceptence / rejection dari request yang terkait. Selain itu cause value dapat menunjukkan penyebab tertentu untuk request yang terkait. Cause value tersebut akan dimasukkan dalam GTP response message.

Berikut list Cause code untuk GTP berdasarkan 3GPP TS 29.060 V12.5.0 dan 3GPP TS 24.008 V12.6.0

Cause value	Cause	Description
##	GTP Request	###
0	Request IMSI	"Request IMSI" used by GGSN to notify SGSN what to do.
1	Request IMEI	"Request IMEI" used by GGSN to notify SGSN what to do.
2	Request IMSI and IMEI	"Request IMSI and IMEI" are used by GGSN to notify SGSN what to do.
3	No identity needed	"No identity needed" used by GGSN to notify SGSN what to do.
4	MS Refuses	"MS is not GPRS Responding" and "MS Refuses" may be used by SGSN to reject a Network-Requested PDP Context Activation.
5	MS is not GPRS Responding	"MS is not GPRS Responding" and "MS Refuses" may be used by SGSN to reject a Network-Requested PDP Context Activation.
6	Reactivation Requested	"Reactivation Requested" is used by the GGSN while tearing down all the PDP Context(s) associated with same PDN connection. It indicates that the GGSN is requesting UE to re-initiate the PDP Context Activation procedure for the corresponding APN.
7	PDP address inactivity timer expires	"PDP address inactivity timer expires" is used by the GGSN in Delete PDP Context Request(s) to indicate that all the PDP context(s) that share the same emergency PDP address are deleted upon the inactivity timer expiry as specified in 3GPP TS 23.203 [39].
8	Network Failure	"Network failure" is used by the SGSN in the Delete PDP Context Request to indicate that the message is sent due to a network problem.
9	QoS parameter mismatch	"QoS parameter mismatch" is used by the SGSN in the Delete PDP Context Request to indicate that the PDP can not be established due to a QoS parameter mismatch.
10-48	For future use
49-63	Cause values reserved for GPRS charging protocol use (see GTP' in 3GPP TS 32.295 [33])
64-127	For future use
##	GTP Response Accept	####
128	Request accepted	"Request accepted" is returned when a GSN has accepted a control plane request.
129	New PDP type due to network preference	"New PDP type due to network preference" indicates that the MS has requested PDP type IPv4v6 and only IPv4 or IPv6 address is allowed for the PDN based on GGSN operator policy, as specified in sub-clause 9.2.1 in 3GPP TS 23.060 [4].
130	New PDP type due to single address bearer only	"New PDP type due to single address bearer only" indicates that the MS has requested PDP type IPv4v6 and both IPv4 and IPv6 addressing is possible in the PDN but the Dual Address Bearer Flag of the Common Flags IE is set to 0 or the Common Flags IE is absent, or only single IP version addressing is possible in the PDN, as specified in sub-clause 9.2.1 in 3GPP TS 23.060 [4].
131-176	For future use
177-191	Cause values reserved for GPRS charging protocol use (see GTP' in 3GPP TS 32.295 [33])
##	GTP Response Reject	####
192	Non-existent	"Non-existent" indicates a non-existent or an inactive PDP context.
193	Invalid message format	If a GTP entity receives a Request message within an IP/UDP packet of a length that is inconsistent with the value specified in the Length field of the GTP header, then the receiving GTP entity should log the error and shall send the Response message with Cause IE value set to "Invalid message format".
194	IMSI/IMEI not known	"IMSI/IMEI not known" indicates a non-existent MM context.
195	MS is GPRS Detached	"MS is GPRS Detached" indicates an idle MM context.
196	MS is not GPRS Responding	"MS is not GPRS Responding" and "MS Refuses" may be used by SGSN to reject a Network-Requested PDP Context Activation.
197	MS Refuses	"MS is not GPRS Responding" and "MS Refuses" may be used by SGSN to reject a Network-Requested PDP Context Activation.
198	Version not supported	"Version not supported" is returned when the recipient does not recognise the version number in the request message.
199	No resources available	"No resources available" is a generic temporary error condition indicating that some kind of resource is used up for that moment excluding the conditions all dynamic PDP addresses are occupied and no memory is available.
200	Service not supported	"Service not supported" is a generic error indicated that the GSN do not support the requested service.
201	Mandatory IE incorrect	In a received GTP signalling message Request, which has a valid length, a mandatory or a conditional extendable length TLV format information element may have a Length field value, which is different from the expected Length . In this case, if the Length field value is greater than expected, the extra unknown octets shall be discarded. if the Length field value is less than the number of fixed octets defined for that IE, preceding the extended field(s), the receiver shall try to continue the procedure, if possible. Otherwise, this information element shall be discarded, the error should be logged, and a Response shall be sent with Cause set to "Mandatory IE incorrect".
202	Mandatory IE missing	The receiver of a GTP signalling Request message with a missing mandatorily present information element shall discard the request, should log the error, and shall send a Response with Cause set to "Mandatory IE missing"
203	Optional IE incorrect	All optional information elements that are incorrect in a GTP signalling message shall be treated as not present in the message. However, if the receiving node may not handle the message correctly because of the incorrect information element, the receiving node should log the error and shall return a response with Cause set to "Optional IE incorrect".
204	System failure	"System failure" is a generic permanent error condition.
205	Roaming restriction	"Roaming restriction" indicates that the SGSN cannot activate the requested PDP context because of the roaming restrictions.
206	P-TMSI Signature mismatch	"P-TMSI Signature mismatch" is returned if either: the P-TMSI Signature stored in the old SGSN does not match the value sent by the MS via the new SGSN; or the MS does not provide the P-TMSI Signature to the new SGSN while the old SGSN has stored the P-TMSI Signature for that MS.
207	GPRS connection suspended	"GPRS connection suspended" indicates that the GPRS activities of the mobile station are suspended.
208	Authentication failure	"Authentication failure" indicates that the user authentication failed in the new SGSN.
209	User authentication failed	"User authentication failed" indicates that the external packet network has rejected the user's service request.
210	Context not found	"Context not found" indicates that the PDP Context referenced in an Active Secondary Context Request message was not found in the receiving GGSN.
211	All dynamic PDP addresses are occupied	"All dynamic PDP addresses occupied" indicates that the GSN does not have a free dynamic PDP address to allocate any longer.
212	No memory is available	"No memory available" indicates that the GSN does not have enough memory to use.
213	Relocation failure	"Relocation failure" indicates that the SRNS relocation failed in the new SGSN side.
214	Unknown mandatory extension header	"Unknown mandatory extension header" signals in a response message that the corresponding request included an extension header for which comprehension was required but unknown to the receiving end.
215	Semantic error in the TFT operation	This cause code is used by the network or the MS to indicate that there is a semantic error in the TFT operation included in a secondary PDP context activation request or an MS-initiated PDP context modification or a network requested secondary PDP context activation.
216	Syntactic error in the TFT operation	This cause code is used by the network or the MS to indicate that there is a syntactical error in the TFT operation included in a secondary PDP context activation request or an MS-initiated PDP context modification or a network requested secondary PDP context activation.
217	Semantic errors in packet filter(s)	This cause code is used by the network or the MS to indicate that there is one or more semantic errors in packet filter(s) of the TFT included in a secondary PDP context activation request or an MS-initiated PDP context modification or a network requested secondary PDP context activation.
218	Syntactic errors in packet filter(s)	This cause code is used by the network or the MS to indicate that there is one or more syntactical errors in packet filter(s) of the TFT included in a secondary PDP context activation request or an MS-initiated PDP context modification or a network requested secondary PDP context activation.
219	Missing or unknown APN	"Missing or unknown APN" indicates e.g. when the GGSN does not support the Access Point Name.
220	Unknown PDP address or PDP type	"Unknown PDP address or PDP type" indicates when the GGSN does not support the PDP type or the PDP address.
221	PDP context without TFT already activated	"PDP context without TFT already activated" are indications of abnormal cases involving TFTs. The abnormal TFT cases and the use of the cause codes are defined in 3GPP TS 24.008 [5].
222	APN access denied – no subscription	"APN access denied – no subscription" indicates that the GGSN has denied the user access to an APN because a subscription is required, but the subscriber does not have the necessary subscription.
223	APN Restriction type incompatibility with currently active PDP Contexts	"APN Restriction type incompatibility with currently active PDP Contexts" conveys to an SGSN that a PDP Context was not allowed to be created or moved by the GGSN because if it had been created or moved, the rules for PDP Context coexistence as described in 3GPP TS 23.060 [4], sub‑clause 15.4, would have been broken.
224	MS MBMS Capabilities Insufficient	"MS MBMS Capabilities Insufficient" is used by the SGSN to notify the GGSN that the MS MBMS Bearer Capabilities are less than the Required MBMS Bearer Capabilities.
225	Invalid Correlation-ID	"Invalid Correlation-ID" indicates that the Correlation-ID was already in use in the SGSN.
226	MBMS Bearer Context Superseded	"MBMS Bearer Context Superseded" indicates that the SGSN has already established an MBMS bearer plane with another GGSN.
227	Bearer Control Mode violation	"Bearer Control Mode violation" indicates that a request is violating the current Bearer Control Mode.
228	Collision with network initiated request	"Collision with network initiated request" indicates that the UE-initiated request was rejected since the network has requested a secondary PDP context activation for the same service using a network-initiated procedure.
229	APN Congestion	"APN Congestion" indicates that the GGSN has detected congestion for the requested APN and performs overload control for that APN which does not allow the PDP Context to be created.
230	Bearer handling not supported	"Bearer handling not supported" indicates that the request was rejected because the respective procedure (MS initiated Secondary PDP Context Activation procedure or the PDP Context Modification procedure), which is related to an established PDP context for LIPA or for SIPTO at the local network, is not supported.
231	"Target access restricted for the subscriber"	"Target access restricted for the subscriber" is used by the MME/SGSN in the Context Response message to indicate that the target access is prohibited for the subscriber, based on the subscription profile.

Berikut beberapa contoh capture GTP message saat proses PDP context

1. Contoh GTP message saat Create PDP context response dengan cause value 222
2. Contoh GTP message saat Create PDP context response dengan cause value 128
3. Contoh GTP message saat Delete PDP context response dengan cause value 192
4. Contoh GTP message saat Update PDP context response dengan cause value 209

Sumber: 
1. 3GPP TS 29.060 V12.5.0 (2014-06)
3rd Generation Partnership Project;
Technical Specification Group Core Network and Terminals;
General Packet Radio Service (GPRS);
GPRS Tunnelling Protocol (GTP)
across the Gn and Gp interface
(Release 12)

2. 3GPP TS 24.008 V12.6.0 (2014-06)
3rd Generation Partnership Project;
Technical Specification Group Core Network and Terminals;
Mobile radio interface Layer 3 specification;
Core network protocols; Stage 3
(Release 12)