Exception Codes [PDF]

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EXCEPTION CODES Exception Code= 171: - cause code 14 : this is reflected by pmNoRrcReqDeniedAdmUlHw, this cause code means that more RAX boards need to be added to the RBSs in order to meet the uplink requirements. many admission rejects due to a lack of uplink channel elements which will trigger soft congestion. - cause code 15 : RbsDlHwResources this can be seen by pmNoRrcReqDeniedAdmDlHw, this exception means that more Tx boards need to be added in order to meet the downlink requirement for channel elements. - cause code 16 : PhysHsChanLimit. maxNumHsdpaUsers 4 is surpassed (license allows maximum of 4). example more then 4 HS users were trying to make calls, but license only allows 4 HSDPA users. The solution is to load a license allowing more HS users and to change parameter maxNumHsdpaUsers to reflect the new license. . - cause code 19 (similar to 17-20): SF16UL limitation --->This number needs to be increased in order to avoid this accessibility restriction for SH16UL which corresponds for example to RAB HS/64. example SF16UL set to 16 meaning that the utrancell will only allow 16 radiolinks with spreading factor 16. The analysis shows that this number has to be increased in order to meet the traffic requirement. - cause code 22 : EdchLimitServingCell, maxNumEulUsers = 4, license allows 16, thus number of eul users for this cell should be increased to allow for eul users. -cause code 5 : DlCode. This can be seen by counter pmNoRrcReqDeniedAdmDlChnlCode. This exception occurs when there is a shortage of channelization codes. RRC is rejected because all the codes are used up. A solution to this problem is to either deploy another carrier or another RBS in order to offload the traffic - cause code 25: The number of HS users with 2ms TTI within serving cell is limited by parameter UtranCell::eulServingCellUsersAdmTti2 (default is 4). When more than eulServingCellUsersAdmTti2 UEs attempt to have particular cell as serving cell with 2ms TTI, the exception coed is raised. This may be applicable when changing serving cell, or RAB establishment. It's most probbable, that higher number of this exception codes comes directly from increased PS HS/EUL traffic. Exception Code 7: - causecode = 301 means drhDcRh_noResources. DC overloaded, not evenly allocated, check "stda" command UEs column Exception Code 11: - causecode = 8: CELLO_AAL2NCI_SERVER_OVERLOAD. This reject cause is issued to protect aal2 server because of a possible overload from the application side. Some of the reasons that cause those rejects: reason 1,

the AAL2NCI client is sending bursts of connection establishment requests to the server. The server accepts a limited number (500) of requests (for all clients together), and it will reject all further rejects before it finishes handling at least 10 of them. reason 2, some of the data transfer resources (AAL2RI clients) are not responding fast enough or not responding at all on connect/disconnect requests received from the AAL2RI server (the same program as AAL2 NCI server) thereby delaying the moment when the server will be able to accept new connection establishment requests. - causecode = 411: Problem seen in DRH allocating traffic beared in the internal CPP AAL2 reservation function. Even in IP configuration 3820 still uses ATM for internal communication. - causecode = 406: drhTrBr_cppNciNodeConnRej ( NCI rejected the local AAL2 connection request. It could be connetion between DC SP and ET board. - causecode 67108962: This cause indicates that there are currently no AAL2AP program that could serve current CelloAal2Nci_netConnectReq(). The AAL2AP program is handling the signalling to the peer node. There are two possible reasons for this. reason 1 the AAL2AP program is temporarilly down due to a (re)start. reason 2 the rpuId specified for the Aal2Ap object is not running in active mode - causecode = 83886257: AAL2 Congestion. Solution 1: Add three aal2paths (QOS CLASS A,B,C) in congestion Iublink. Impact Small. Only add some new MOs, no modify or delete Solution 2: Increase egressAtmPcr in AtmTrafficDescriptor. Impact Medium. SW Configuration Change. Some MOs have to be changed Solution Exception Code 11: Change the Iub over ATM to IP Transport. Impact Large. Both SW and HW Configuration change - causecode = 83886258 and causecode = 405: the reason is that current connection requires a bandwidth greater than the bandwidth available on any of the paths towards that node. The congestion will remain until at least one connection towards that node has been released: Exception Code 12: Received signal faultyTrBrInd. IUC Initialisation procedure wasn’t completed successfully. Either the Initialisation Frames werent sent from the MSC or were lost in the Transport Network. lock each Aal2path towards MSC individually. Exception Code 23: - Cause code 334: Cause 1 CNID modification on the RNC. the URA to FACH succ rate will drop to 0% temporarily. Cause 2 Capacity crossed on all PDR devices which can be checked via coli command: lh mod drh_pdrrh. Cause 3. PDR load spike reported to DRH. SP sends load status in pdrLoadStatusInd and it can be Low, Medium or High. When High load is reported by sp, status flag is set to LoadHigh and sp becomes unavailable for Rab resuming. Exception Code 40: - causecode = 0: DC devices lost and DcRh can't use them. In DcRh there is a fault protection mechanism to removes the devices that are not

attached within 20 seconds. This mechanism prevents hangings. See SCS1094225 Exception Code 54: This exception is generated when maximum number of retransmissions are performed on RLC and reset - causecode = 1: seen in conjunction the exceptions EC521/523/552. In many cases an RLC reset has occurred due to max number of RLC retransmissions being sent. - causecode = 101: seen with problems with primary scrambling codes or other misconfiguration in cells. rBId 16 or 17, “Processing failure on PS rbId = 16, release PS Rab(s)” involving UeRc=54, sourceConnType = uehPsInt64HsPsInt64Hs. This is raised when the UE initiates an RLC reset due to the mis-match in PDU size Exception Code 58: - causecode=1, CELL_NOT_IN_NEIGHBOURSET, means that a proposed cell to be added to an Active Set is not part of the neighbour list. Generally this means checking that neighbour lists are correct and reconfiguring as needed. This may be a symptom of an issue reported in PLM Info 717 which can affect this RNCs SW Release, W10.1.3.3. Exception Code 110: Received signal messageReject on UehNbapDedicatedP. - cause code 1: Encode failed, cause code 2: Timeout, cause code 3: Transaction removed. Either network overload or link disturbances. Investigate loss of RadioLinkSetupRequestFDD or RadioLinkReconfPrepare messages between the SRNC and RBS, or response messages not being sent back by the RBS Exception Code 122: incorrectly stored conn id is being used by a drift context. In this case when RabEstablishDedToCom is deported an SCCP disconnect is sent towards the SRNC, generating the exception in the SRNC Exception Code 130: Incorrectly stored conn id is being used by another serving context which has a drift RL set up. In this case when RabEstablishDedToCom is deported and SCCP disconnect is sent towards the DRNC, generating the exception in the DRNC Exception Code 142: When an IU signalling connection is being set up for a UE Connection, the signal uehRanapInitialUeReq is sent from UEH via RNH to the CN. In response to this request a uehRanapInitialUeRej could be returned by RNH to indicate that the connection setup failed. If uehRanapInitialUeRej is received in the SignConnSetup procedure with "disconnectType = abnormaldisconnect" then UEH Exception 142 is raised. Exception Code 160: RRC Request failures caused by too high ModMP CPU load. The ModMP start rejecting RRC Request when the CPU load reaches 85%. Verify with counter pmNoRejRrcConnMpLoadC Exception Code 181: Received signal connRejV2 on UehUeCtxtProcCpxAal2NciP. Enter the rejectType = X & causeCode = XXXXXXX

in the form on the AAL2 troubleshooting web page to get decoded information: http://www.design.etk.extern.eu.ericsson.se/DEPARTMENTS/ETK_D_C/sys_mng/n ch_i_v/aal2_hints.shtml Exception Code 223: result of decreased available resources in the node. Similar to 171 Exception Code 262: Failed to allocate a UeContext in UEH. Too many Hanging Drift UE Ctxts. See Primus SCS921790 Exception Code 310: Received signal NBAP RADIO LINK SETUP FAILURE. Cause code: 0, unknown_CID, 1 cell_not_available, 2 power_level_not_supported. - cause nodeB-resource-unavaiable: The reason for this issue is RBS running out of resource, especially when to allocate E-DBCH for AGCH. This indicates that the issue for this EC310 is simply heavy traffic load. Exception Code 311: Received signal NBAP RADIO LINK ADDITION FAILURE. Cause code: 0, unknown_CID, 1 cell_not_available, 2 power_level_not_supported. Exception Code 312: NBAP RadiolinkReconfigurationFailure - cause REQUESTED_CONFIGURATION_NOT_SUPPORTED: Missing information in NBAP message RL Reconfiguration Prepare. Exception Code 327: Received signal NBAP RADIO LINK FAILURE INDICATION. If UehDriftUeCtxtC: This happens when the connid which was incorrectly released is reselected for a new incoming SCCP connection. When this happens UEH detects that there are two UeRef associated with same connid – the hanging Drift Context and new Drift Context allocated for the incoming RL Setup Request. UEH then triggers a release of the hanging Drift Context. It is also possible that the SCCP disconnect is received during deletion of the last RL in the DRNC. In this case, the RL in the drift RBS will have been released but the context will not since SRNC cannot send SCCP disconnect to DRNC. Exception Code 400: The UE rejects the radioBearerSetup sent by the RNC with failure cause : Invalid Configuration. Check radioBearerSetup messages fo abnormal fields sent by the RNC. seen with qualcomm chipset MSM6275/MSM6280. Exception Code 401: UE receives SECURITY MODE COMMAND message with variable INCOMPATIBLE_SECURITY_RECONFIGURATION=true, UE shall send SECURITY MODE FAILURE message to RNC. RNC issues exception 401. Normal behavior Exception Code 407: Received signal RRC CellUpdate with Failure Cause. Cell Update fails, UE in FACH release call

Exception Code 451: Received signal RANAP Relocation Preparation Failure. Problem with IRAT handover Exception Code 456: Received signal RANAP Initial Ue Reject. Investigate Transport and Core Networks Exception Code 504: TIMER T_RABREL_1 has expired waiting for RRC Radio Bearer Release Response. Possible reasons for that: reason 1) The PS RAB has some problem, such as faulty TrBr was reported, then UEH will drop the whole call, so the CS call drop rate has also been affected. reason 2)It’s timeout when waiting for Radio Bearer Release Response from UE. reason 3) whether the UE has received the release request message. the request message may not reach UE OR UE received the message, but decoded error or too high BLER, UE can’t understand the message. OR UE decoded the request normally and sent out the response correctly, but RNC lost the message. After the timer’s time-out, the UE has been dropped. Exception Code 509: This covers the scenario where the UE is in compressed mode and a timer expires while the RNC is waiting for a message from the UE. The RNC sends RRC PhysicalChannelReconfiguration to order the Ue to the new configuration on the RL. Once this RRC message is sent, a timer "tcpmPcr" (5 seconds) is started and the RNC waits for PhysicalChannelReconfigurationComplete from the UE. If this is never received the timer expires and UEH Exception above is triggered. Exception Code 512: This Exception can be raised when there is a problem trying to perform IRAT CC UTRAN to GSM. Exception Code 521: "TIMER rrcSetuptimerId has expired; InterfaceTimout". Occurs when Neither RRC Connection Setup Complete or NBAP Radio Link Restore Indication received This Exception can be sometimes be associated with Synchronization issues between RNC and RBS, but no NodeSynch alarms were observed from the RNC. Further investigation of the sites affected would be needed to clarify the exact cause of this Exception. Exception Code 523: Exception if expires: Timeout waiting for Active Set update complete. In the soft handover procedure, timeout waiting for ASU complete message. If the RNC does not receive either ACTIVE SET UPDATE COMPLETE or ACTIVE SET UPDATE FAILURE message before the timer tRrcActiveSetUpdate is expired, the RNC considers the communication with the UE to be lost. This results in the connection being released and a RANAP Iu Release Request is sent. This is normal system behaviour. The system does not maintain the UE connection when the timer expires, the call is released. The occurrence of EC523 indicates the customer may have coverage issues in their network and need to perform RF optimization. There may also be missing neighbour relations or incorrectly configured primary scrambling codes. Exception Code 529 inactivityDchTimerId has expired. The inactivity timer expires due to a lack of, for example, RANAP RAB Assignment Request – investigate MSC. RNC considers this type of release a normal release see pmNoNormalNasSignReleaseCs pegging and not pmNormalSystemNasSignReleaseCs Exception Code 545: Timeout RRC SecurityModeComplete not received

Exception Code 552: “TIMER T_CH_SWITCH_1 has expired” Here the UE has not responded during a Channel Switching procedure. Further investigation required on the cells affected. From the DCG it is interesting to note that nearly all the channel switching transitions involved DCH -> FACH. This could suggest that UE lost contact with the network initially leading to channel switching due to UE Inactivity which then experienced this timeout. Exception Code 554: Internal timing issue in the RNC when executing Channel Switch. This CFN handling applies at Radio Bearer Setup and at Radio Link Reconfiguration. At synchronised reconfigurations the RNC decides at which point in time the reconfiguration shall take place. This point in time is called the activation time for the reconfiguration and it is signalled to both the RBS and UE in order for them and for the RNC to perform the reconfiguration at exactly the same time. The activation time is given as a Connection Frame Number (CFN). Exception Code 562: related to the releasing of SCCP connections Exception Code 563 This exception is generated when all radio links in the Active Set have lost synch, i.e. NBAP Radio Link Failure cause synchronization failure is received for all RLs. The exception is generated after 5s timeout. Often optimization issue. Example reasons: 1) UE for some reason stopped sending DPCCH (turns of transmitter). For example battery is empty/removed…. 2) UE for some reason suddenly disappears from the range of the RBS. The change in RF must be so sudden that power control is unable to adapt the power levels. For example walks around the corner of a building, jumps into a train/car/bus… 3) UE/RBS for some reason send/receive DPCCH with the wrong scrambling code or DPCCH format. Mismatch in configuration between RBS and UE. 4) UE has timed out on one of the RLC-bearers (max number of retransmissions followed by RLC Resets). UE is then forced to turn off TX and return to Idle. 5) Simply a UE crash or UE fault for unknown issues. Remember that Utran (RBS & RNC) is usually unaware of internal problems in UE. In most cases, an unexpected UE crash would be noticed by Utran as "loss-ofULsynch"- EC563. 6) If the UE is engaged in a multiRAB, then problems on PS side (e.g. transport NW issues) can result in RLC problems and that UE is forced to go to Idle. Exception Code 564: Timeout: The RNC (more accurately the allocated DC device) sends Initialisation message to the MGW to negotiate the codec type, but no response is received. RNC initiates release procedure by sending a RAB-AssignmentResponse ( cause:radioNetwork/iu-up-failure) to the MSC. Exception Code 594: “Received signal initialUeIdCollisionActionReq” This exception is commonly called UE Id Collision and can occur for scenarios involving both speech and PS/HS. A UE Id collision EC594 is triggered when the RNC detects a new RRC connection for a UE that the RNC already has an existing RRC connection for. The race condition is that the UE has lost connectivity with the network and tries to access again with a new RRC connection request before the RNC has actually detected and released the RRC connection for the loss of contact with the UE. In this case, the exception code 594 is triggered as only one RRC connection is possible. The delay in the RNC releasing the connection can be due to

“loss of contact” timers. The rcLost timer controls how long RNC waits after losing a connection before releasing the resources. The purpose of these timers is to reduce the number of dropped calls because the UE may come back in synchronisation on the radio link before this timer expires which will recover the call. This is just an example of where the network is delaying releasing the RRC resources. The behaviour on the UE side can be different between vendors resulting in UE retrying RRC connection before RNC has released the previous RRC connection. Please refer to PLM Info 562 for changes in behaviour of this Exception after P7.1. Exception Code 595: UE doesn’t reply to physical channel reconfiguration complete message. Possible reason for that: a) UE doesn’t support URA_PCH state. b)Some problem with synch between network and UE, maybe poor RF condition. Exception Code 654: OGICAL ERROR IN NBAP RADIO LINK RECONF RESPONSE. Decode and troubleshoot NBAP RadioLinkReconfigurationReady message, for missing information. Exception Code 702: LOGICAL ERROR IN RNSAP RADIO LINK ADDITION REQUEST. RNC in DRNC role didn't understand the information from SRNC in RadioLinkAdditionRequest message Exception Code 756: logical error in rrc radio bearer reconf Message in DL, so the UE thinks that the message is wrong Exception Code 757: logical error in rrc radio bearer reconf complete Message in UL, in this case is the RNC that does not like the answer from the UE. Exception Code 900: unallocated UeCtxt in UEH receives the unexpected chSwitchEvalInd signal from DCS, this is caused by UE hanging /status mismatch between UEH, DCS, DRH, And UEH will then send startSpAuditInd to DCS to init audit between UEH/DCS/DRH, and finally all hanging UEs should be released. It has nothing to do with the RRC rejection. Exception Code 930: when the RNC rejects : 1. Cell Update with cause uplinkDataTransmission when UE on Common Channel 2. Cell Update with cause cellReselection when UE on URA_PCH

Exception Code 947: Failed handover of EUL/HS call and release due to DCS set relOnReject = True. The reason for failed handover is when there is only one cell in active set, target cell not supporting HS or EUL.