Cause values for mobility.doc

Cause values for mobilitymanagement

Postedby:Caterpillaron:September 9, 2010 In:NAS

1CommentCauses related to MS identification

Cause value = 2 IMSI unknown in HLR

This cause is sent to the MS if the MS is not known (registered) in the HLR. This cause code does not affect operation of the GPRS service, although is may be used by a GMM procedure.

Cause value = 3 Illegal MS

This cause is sent to the MS when the network refuses service to the MS either because an identity of the MS is not acceptable to the network or because the MS does not pass the authentication check, i.e. the SRES received from the MS is different from that generated by the network. When used by an MM procedure, except the authentication procedure, this cause does not affect operation of the GPRS service.

Cause value = 4 IMSI unknown in VLR

This cause is sent to the MS when the given IMSI is not known at the VLR.

Cause value = 5 IMEI not accepted

This cause is sent to the MS if the network does not accept emergency call establishment using an IMEI or not accept attach procedure for emergency services using an IMEI.

Cause value = 6 Illegal ME

This cause is sent to the MS if the ME used is not acceptable to the network, e.g. blacklisted. When used by an MM procedure, this cause does not affect operation of the GPRS service.

Cause related to subscription options

Cause value = 11 PLMN not allowed

This cause is sent to the MS if it requests location updating in a PLMN where the MS, by subscription or due to operator determined barring is not allowed to operate.

Cause value = 12 Location Area not allowed

This cause is sent to the MS if it requests location updating in a location area where the HPLMN determines that the MS, by subscription, is not allowed to operate.

NOTE: If cause #12 is sent to a roaming subscriber the subscriber is denied service even if other PLMNs are available on which registration was possible.

Cause value = 13 Roaming not allowed in this location area

This cause is sent to an MS which requests location updating in a location area of a PLMN which by subscription offers roaming to that MS but not in that Location Area.

Cause value = 15 No Suitable Cells In Location Area

This cause is sent to the MS if it requests location updating in a location area where the MS, by subscription, is not allowed to operate, but when it should find another allowed location area in the same PLMN.

NOTE: Cause #15 and cause #12 differ in the fact that cause #12 does not trigger the MS to search for another allowed location area on the same PLMN.

Cause value = 25 Not authorized for this CSG

This cause is sent to the MS if it requests access in a CSG cell where the MS either has no subscription to operate or the MSs subscription has expired and it should find another cell in the same PLMN.

NOTE: The MS not supporting CSG will not receive cause# 25, as such a MS is not supposed to try to access a CSG cell.

Causes related to PLMN specific network failures and congestion/Authentication Failures

Cause value = 20 MAC failure

This cause is sent to the network if the USIM detects that the MAC in the AUTHENTICATION REQUEST or AUTHENTICATION_AND_CIPHERING REQUEST message is not fresh (see 3GPP TS 33.102 [5a]).

Cause value = 21 Synch failure

This cause is sent to the network if the USIM detects that the SQN in the AUTHENTICATION REQUEST or AUTHENTICATION_AND_CIPHERING REQUEST message is out of range (see 3GPP TS 33.102 [5a]).

Cause value = 17 Network failure

This cause is sent to the MS if the MSC cannot service an MS generated request because of PLMN failures, e.g. problems in MAP.

Cause value = 22 Congestion

This cause is sent if the service request cannot be actioned because of congestion (e.g. no channel, facility busy/congested etc.).

Cause value = 23 GSM authentication unacceptable

This cause is sent to the network in Iu mode if a USIM is inserted in the MS and there is no Authentication Parameter AUTN IE present in the AUTHENTICATION REQUEST or AUTHENTICATION_AND_CIPHERING REQUEST message.

Causes related to nature of request

Cause value = 32 Service option not supported

This cause is sent when the MS requests a service/facility in the CM SERVICE REQUEST message which is not supported by the PLMN.

Cause value = 33 Requested service option not subscribed

This cause is sent when the MS requests a service option for which it has no subscription.

Cause value = 34 Service option temporarily out of order

This cause is sent when the MSC cannot service the request because of temporary outage of one or more functions required for supporting the service.

Cause value = 38 Call cannot be identified

This cause is sent when the network cannot identify the call associated with a call re-establishment request.

Causes related to invalid messages

Cause value = 95 Semantically incorrect message.

See annex H, subclauseH.5.10.

Cause value = 96 Invalid mandatory information.


Cause value = 97 Message type non-existent or not implemented.


Cause value = 98 Message not compatible with protocol state.


Cause value = 99 Information element non-existent or not implemented.


Cause value = 100 Conditional IE error.


Cause value = 101 Message not compatible with protocol state.


Cause value = 111 Protocol error, unspecified.


Additional cause codes for GMM

Cause value = 7 GPRS services not allowed

This cause is sent to the MS when it is not allowed to operate GPRS services.

Cause value = 8 GPRS services and non-GPRS services not allowed

This cause is sent to the MS when it is not allowed to operate either GPRS or non-GPRS services.

Cause value = 9 MS identity cannot be derived by the network

This cause is sent to the MS when the network cannot derive the MSs identity from the P-TMSI in case of inter-SGSN routing area update.

Cause value = 10 Implicitly detached

This cause is sent to the MS either if the network has implicitly detached the MS, e.g. some while after the Mobile reachable timer has expired, or if the GMM context data related to the subscription dose not exist in the SGSN e.g. because of a SGSN restart.

Cause value = 14 GPRS services not allowed in this PLMN

This cause is sent to the MS which requests GPRS service in a PLMN which does not offer roaming for GPRS services to that MS.

Cause value = 16 MSC temporarily not reachable

This cause is sent to the MS if it requests a combined GPRS attach or routing are updating in a PLMN where the MSC is temporarily not reachable via the GPRS part of the network.

Cause value = 40 No PDP context activated

This cause is sent to the MS if the MS requests an establishment of the radio access bearers for all active PDP contexts by sending a SERVICE REQUEST message indicating data to the network, but the SGSN does not have any active PDP context(s).

PDP Activation failed Possible Root Cause

postedApr 4, 2012, 10:05 PMby Aswadi Abdul Rahman"No resources available" indicates that not enough resources are available within the network to allow the PDP Context to be created. "Missing or unknown APN" indicates e.g. when the GGSN does not support the Access Point Name. "Unknown PDP address or PDP type" indicates when the GGSN does not support the PDP type or the PDP address."User authentication failed" indicates that the external packet network has rejected the service requested by the user e.g. the authentication check in the RADIUS server failed. "PDP context without TFT already activated" indicates that a PDP context has already been activated without a TFT for that MS. "Context not found" indicates that a Create PDP Request for a subsequent PDP context has been received, but the PDP context associated with the request, which the SGSN believes to be active does not exist on the GGSN. "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."New PDP type due to network preference" indicates that the GGSN has selected a PDP type different from the one sent by the MS. "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 bitof 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.

A look at PDP Context in UMTS networks

By Zahid Ghadialy

Last Updated: 04/11/2007

Packet Data Protocol (PDP)

A Packet Data Protocol (PDP) context offers a packet data connection over which the UE and the network can exchange IP packets. Usage of these packet data connections is restricted to specific services. These services can be accessed via so-called access points.

Packet Data Protocol Context is one of the most important concepts for the UMTS Packet Data Architecture.

The PDP Context has a record of parameters, which consists of all the required information for establishing an end-to-end connection:

PDP Type

PDP address type

QoS profile request (QoS parameters requested by user)

QoS profile negotiated (QoS parameters negotiated by network)

Authentication type (PAP or CHAP)

DNS type (Dynamic DNS or Static DNS)

The PDP Context is mainly designed for two purposes for the terminal.

Firstly PDP Context is designed to allocate a Packet Data Protocol (PDP) address, either IP version 4 or IP version 6 type of address, to the mobile terminal.

Secondly it is used to make a logical connection with QoS profiles, the set of QoS attributes negotiated for and utilized by one PDP context, through the UMTS network.

Multiple PDP Context

As mobile phones develop, there will be a need to serve parallel applications running on them with simultaneous PS calls. These PS calls can differ in their QoS (Quality of Service) parameters, and/or in the target network (PDN Packet Data Network) to which they provide connection.

Multiple PDP Contexts means that one mobile terminal can have multiple PDP contexts. Each of the Multiple PDP Contexts can at the same time have different QoS profiles. The primary PDP Context is a normal PDP Context with default QoS profile attributes and it is always activated first. For the multiple primary PDP Contexts, each context has different PDP Address and different APN

Multiple PDP contexts will have special significance when IMS is introduced and all the services will be PS (IP) based. In an IMS based network the MS can (and will) activate separate PDP contexts for SIP based signaling and for all the sessions of different, eventually parallel services (e.g. parallel VoIP call and PS data call, etc.). A different QoS which matches the application - will be used for each connection.

The data flow (user plane) of a particular PDP context can terminate either in the Mobile Terminal (MT) itself or in the connected Terminal Equipment (TE) as shown in Figure below. The application for which the connection is provided is running either on the MT or on the TE respectively. An example for the first possibility is a video telephony client running on the mobile, for the second possibility a web browser running on the connected notebook.

In IMS based systems it is expected that several embedded applications will run on the MT, requiring multiple PDP contexts. For the TE (e.g. connected PC) one additional PDP context may be also active.

Multiple PDP contexts have two sub-categories:

1. multiple primary PDP contexts: they provide connections to different PDNs

2. secondary PDP contexts: they provide connections to the same PDN but with different QoS

Multiple Primary PDP Contexts

Multiple primary PDP contexts are two or more PDP contexts independent from one another, each of them using one unique PDP address. They give the possibility to have simultaneous connections to different PDNs e.g. to the internet for one application, while to a private network for another one.

Beside the unique PDP address, each PDP context has its own QoS and NSAPI (Network Layer Service Access Point Identifier, see later) assigned. Each PDP context has a separate RAB (Radio Access Bearer) and GTP tunnel to transfer user plane data.

The PDP contexts typically terminate in different access points on the network side (although it is allowed that they terminate in the same access point). The terminating access points can be located in the same or in different GGSNs.

The example in Figure below shows the user plane path for three primary PDP contexts providing connections to three different PDNs:

Primary PDP contexts can be activated or deactivated independently from one another. QoS of any of the active PDP contexts can be modified with the PDP context modification procedure initiated by the MS or by the network. (See Below for details)

Secondary PDP Contexts

A secondary PDP context is always associated with a primary PDP context. PDP address (IP address) and access point (AP) is re-used from the primary context. Hence the primary and the associated secondary PDP context provide connection to the same PDN with different guaranteed QoS.

One primary PDP context might have multiple secondary contexts assigned. Each PDP context (i.e. the primary and all secondary) has its own RAB and GTP tunnel to transfer user plane data. Also, each context is identified by a unique NSAPI (Network Layer Service Access Point Identifier).

The primary PDP context has to be active prior to activating an associated secondary PDP context. Any secondary PDP context can be deactivated while keeping the associated primary context (and eventual other secondary PDP contexts) active. If a primary PDP context is deactivated, this will also deactivate all the assigned secondary PDP contexts. QoS of any active primary or secondary PDP context can be modified with the PDP context modification procedure initiated by the MS or by the network. (See below for details)

As the PDP address (IP address) is common for the primary and for (all) the associated secondary PDP contexts, the TFT (Traffic Flow Template) is introduced to route downlink user plane data into the correct GTP tunnel and hence into the correct RAB for each context.

The example in Figure below shows the user plane for a primary and two associated secondary PDP contexts:

Combination of multiple primary PDP contexts and secondary PDP contexts is also possible. For example, two primaries with one secondary context for each will result in four active PDP contexts in total. The maximum number of supported PDP contexts is terminal dependent.

Traffic Flow Template (TFT)

The Traffic Flow Template (TFT) is used by GGSN to discriminate between different user payloads. The TFT incorporates from one to eight packet filters; a unique packet filter identifier identifies each filter. Filtering can be based on one or more of the following filter attributes:

Source address (with subnet mask)

IPv4 protocol number

Destination port range

Source port range

IPSec Security Parameter Index (SPI)

Type of Service (TOS) (IPv4)

The TFT is provided by the MS in the Activate Secondary PDP Context Request message, it is stored by the GGSN, and is examined when routing downlink user plane data. The TFT can be modified or deleted with the MS initiated PDP context modification procedure. A TFT may be also assigned to a primary PDP context by means of the MS initiated PDP context modification procedure.

A TFT is built up from Packet Filters (minimum 1, maximum 8 of them) to provide flexibility in filtering. The relationship between PDP contexts, TFTs and Packet Filters is illustrated in Figure below:

PDP context procedures

Primary PDP context activation

This procedure is used to establish a logical connection with the Quality of Service (QoS) functionality through the network from the UE to the GGSN. PDP context activation is initiated by the UE and changes the session management state to active, creates the PDP context, receives the IP address and reserves radio resources. After a PDP context activation the UE is able to send IP packets over the air interface. The UE can have up to 11 PDP contexts active concurrently.

Secondary PDP context activation

A secondary PDP context activation allows the subscriber to establish a second PDP context with the same IP address as the primary PDP context. The two contexts may have different QoS profiles, which makes the feature useful for applications that have different QoS requirements (e.g., IP multimedia). The access point name, though, will be the same for the primary and secondary PDP contexts.

PDP context modification

The UE, the SGSN or the GGSN initiate this procedure for updating the corresponding PDP context. Additionally, the radio access network is able to request a PDP context modification from the SGSN (e.g., when coverage to the UE has been lost). The procedures modify parameters that were negotiated during an activation procedure for one or several PDP contexts.

PDP context deactivation

This procedure is used to delete a particular logical connection between the UE and the GGSN. The initiative to deactivate a PDP context can come from the UE, the SGSN, the Home Location Register (HLR) or the GGSN.

Access points

Access points can be understood as IP routers that provide the connection between the UE and the selected service. Examples of such services are:

Multimedia Messaging Service (MMS);

Wireless Application Protocol (WAP);

direct Internet access;

IP Multimedia Subsystem (IMS).

Depending on the operator of the network, more than one of these services might be provided by the same access point. The UE needs to be aware of an Access Point Name (APN) the address of a GGSN which gives access to the service-providing entity (e.g., an MMSC, the Internet or the P-CSCF). One GGSN may provide different services that can be accessed by different APNs.

When establishing a primary PDP context with an APN the UE receives an IP address or in the case of IPv6 an IPv6 prefix that it has to use when communicating over that PDP context. This means that when a UE has established several connections to different APNs the UE will have different IP addresses for each of the provided services.

REFERENCES

[1] The IMS: IP Multimedia Concepts and Services, Second Edition Miikka Poikselk, Georg Mayer, Hisham Khartabil and Aki Niemi [2] Multiple PDP Contexts in UMTS - ESG Group, Qualcomm [3] 3GPP TS 23.060: "General Packet Radio Service (GPRS); Service description" [4] 3GPP TS 24.008: "Mobile radio interface layer 3 specification; Core Network Protocols" [5] What are Secondary PDP Contexts Good For? - Martins Mobile Technology Blog [6] Using Traffic Flow Templates (TFTs) on BGAN - Inmarsat

TLLI:The TLLI (Temporary Logical Link Identifier) is used in GPRS services for addressing on resources used for communication between the UE and the SGSN. Each TLLI can determine a unique MS context on Gb interface. In Gb mode, the BSC obtains the NRI according to the TLLI. If an MS is assigned with a P-TMSI, the TLLI is derived from the P-TMSI. If an MS is not assigned with a P-TMSI, the TLLI is a random number.

The TLLI consists of 32 bits and can be classified into four groups:1.A local TLLI is built by a MS which has a valid P-TMSI (normal operation)2.A foreign TLLI is built by a MS which has a valid P-TMSI (primarily used when crossing a routing area boundary)3.A random TLLI is built by an MS (used for initial access or if the user equipment does not possess any of the above)4.An auxiliary TLLI is built by the SGSN (is not used as of now)

NSAPI:A Network (Layer) Service Access Point Identifier (NSAPI), is an identifier used in GPRS networks.It is used to identify a PDP context in the MS and SGSN. It is dynamically selected by the MS and it should ensure that the selected NSAPI is not currently being used by another session management entity in the MS. When the MS requests a PDP context, it selects an NSAPI that it sends to the SGSN with the request.

NSAPI is also used as part of the Tunnel Identifier between GSNs.The user identity (IMSI) and the application identifier (NSAPI) are integrated into the TID (GTPv0) or TEID (GTPv1) that uniquely identifies the subscribers sublink between the SGSN and GGSN.The SGSN inserts the NSAPI along with the GGSN address in the Create PDP Context Request. One PDP context may have several (secondary) PDP contexts and NSAPI. The NSAPI is an integer value within the PDP context header.

TFT:TFT is Traffic Flow Template and used by GGSN to discriminate between different user payloads. The TFT incorporates packet filters such as QoS, PDP Context and security. Using the packet filters the GGSN maps the incoming datagrams into the correct PDP Context.When incoming data arrives at an access point in the core network, a packet classifier will make a PDP context selection based on the traffic flow template, and map the incoming data packets into the PDP context with the correct QoS attributes. The use of a traffic flow template allows multiple PDP contexts to be associated with the same PDP address.

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Cause values for mobility.doc