LTE: Deactivate EPS Bearer Context Request

·        The purpose of the EPS bearer context deactivation procedure is to deactivate an EPS bearer context or disconnect from a PDN by deactivating all EPS bearer contexts to that PDN.
·        This procedure is initiated by the network, and it may be triggered by the UE by means of the Bearer Resource Modification or PDN Disconnect procedure.
·        If a NAS signalling connection exists when the MME initiates this procedure, then the MME shall initiate the EPS bearer context deactivation procedure by sending a DEACTIVATE EPS BEARER CONTEXT REQUEST message to the UE and start the timer T3495.
·        If there no NAS signalling connection exists when the MME initiates this procedure, then the ESM entity in the MME shall locally deactivate the EPS bearer context towards the UE without any peer-to-peer ESM signalling between the MME and the UE.
·        The DEACTIVATE EPS BEARER CONTEXT REQUEST message contains an ESM cause typically indicating one of the following:
#8:  operator determined barring
#36: regular deactivation
#38: network failure
#39: reactivation requested or
#112: APN restriction value incompatible with active EPS bearer context
·        If the deactivation is triggered by a UE initiated bearer resource modification or PDN disconnect procedure, the DEACTIVATE EPS BEARER CONTEXT REQUEST message shall contain the PTI value received from the UE in the corresponding message.
·        When the MME wants to deactivate all EPS bearer contexts to a PDN and thus disconnect the UE from the PDN, the MME shall include the EPS Bearer Identity of the default bearer associated to the PDN in the DEACTIVATE EPS BEARER CONTEXT REQUEST message.
·        If the MME doesn’t receive a response for DEACTIVATE EPS BEARER CONTEXT REQUEST before the expiry of the timer T3495, the MME shall resend this message and shall reset and restart T3495. This retransmission is repeated four times, i.e. on the fifth expiry of T3495, the MME shall abort the procedure and deactivate the EPS bearer context locally without any peer-to-peer ESM signalling between the MME and the UE.
·        The IE Protocol Configuration Options is included in the message if the network wishes to transmit (protocol) data (e.g. configuration parameters, error codes or messages/events) to the UE.

Reference 3GPP TS 24.301

Example:  DEACTIVATE EPS BEARER CONTEXT REQUEST message

11 comments:

  1. Can you elaborate more on ESM cause meaning:
    #8: operator determined barring
    #36: regular deactivation
    #38: network failure
    #39: reactivation requested or
    #112: APN restriction value incompatible with active EPS bearer context

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  2. Please check 24.301 Annex A for all cause values.
    #8: operator determined barring
    This ESM cause is used by the network to indicate th at the requested service was rejected by the MME due to Operator Determined Barring

    Cause #36 – Regular deactivation
    This ESM cause is used to indicate a regular UE or network initiated release of EPS bearer resources

    Cause #38 – Network failure
    This ESM cause is used by the network to indicate th at the requested service was rejected due to an error situation in the network

    Cause #39 – Reactivation requested
    This ESM cause is used by the network to request a PDN connection reactivation

    Cause #112 – APN restriction value incompatible with active EPS bearer context.
    This ESM cause is used by the network to indicate that the EPS bearer context(s) have an APN restriction value
    that is not allowed in combination with a currently activ e EPS bearer context. Restriction values are defined in 3GPP TS 23.060

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    Replies
    1. Hi Kumar.
      On my lte modem i receive the following message
      EPS PDN DEACT 5
      What does it mean?

      Delete
  3. Hi,

    Is there a mechanism to alter the PAA (PDN Address Allocation) of the default bearer without deactivating it?
    I need to alter the end user address to pass the packets through a traffic shaper on a trigger in the middle of a session.
    In 3G, I think the GGSN can send an Update PDP Context Request to the SGSN for providing a new end user IP address, but I don't see the equivalent for LTE.
    If deactivating is the only option:
    -- After the Delete Bearer Request/Response for the default bearer, will there be Delete Session Request?
    -- The best "Cause" for the Delete Bearer Request is "Reactivation Requested", isn't it?
    -- Will there be another Create Session Request?

    Thank you very much.

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  4. Hi Kumar,

    can you please share under what scenarios can eNB initiate deactivate EPS bearer with Cause #36 – Regular deactivation


    Thanks
    Ravneet

    ReplyDelete
    Replies
    1. This ESM cause is used to indicate a regular UE or network initiated release of EPS bearer resources. This is cause was value used for regular/normal release of EPS bearer resources

      Delete

  5. Hi Kumar, thanks for the explanation.
    One question, I receive deactivate bearer reguest for QCI5 suddenly when RF conditions are good and call was active. No rtp timeout issue observed. What might be reason? I think it is a timer issue on EPS side.
    Thanks,

    ReplyDelete
    Replies
    1. I am not sure, could there be an issue on the other side of the call?

      Delete
  6. Hi kumaraswamy,

    is there any cause for deactivate the PDN after ims has done successfully that is sip registration .

    can you explain the scenerio.

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  7. can you help why Attach is Rejected (ESM Failure), PDN Connectivity reject (Network Failure) soon after ULR/ULA?

    Why is MME rejecting it?

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  8. Is it normal scenario wherein after receiving Delete Bearer Request from SGW/PGW (Upon LTE to WiFi Handover), MME is neither sending any E-RAB Release Command towards eNB nor sending any Deactivate EPS Bearer Context Request towards UE, however responding with directly with Delete Bearer Response (Success) towards SAEGW. If this is a normal behavior on MMEs part then can you tell some sample scenarios where this could happen.

    ReplyDelete