Emergency PDN support
Release 13 emergency PDN Support
enables UE to make emergency calls when LTE network is not available. This
feature is implemented as defined in 3GPP.
Release 13 Emergency PDN Support features
ePDG will take
incoming call as emergency based on presence of "EMERGENCY" in IDr payload in
Emergency NAI on SWu interface as defined in 3GPP. i.e presence of SOS instead
of nai keyword, though whether call is emergency or not is decided by presence
of IDr "emergency"
ePDG blocks all
other procedures those are not applicable to emergency sessions
configuration option for Emergency data of APN name, PGW identity
(address/FQDN), default QoS and APN-AMBR
previous IKE sessions when an emergency call is setup and ePDG ensures that no
other PDN connections from UE are present when emergency call is setup
Selection AVP will be absent if the UE indicates the establishment of an
emergency session during the IKEv2 tunnel establishment
Emergency-Indication AVP in DER and DEA
ePDG which supports
emergency services will include Emergency-Indication AVP information element if
the UE indicated the establishment of an emergency session during the IKEv2
The 3GPP AAA Server
interprets the receipt of the Emergency-Indication AVP as an indication that
the UE requests to access the EPC for emergency services.
new DPD timer explicit to Emergency Calls
New DPD timer
controlled by CLI for emergency calls is introduced. UE may send non-emergency
call after emergency call without sending delete for emergency call. With this
feature new timer will clear emergency call, post which new non-emergency call
will be handled.
With this timer,
emergency call gets deleted after sometime if the response is not received.
Ideally this timer will be kept low to identify stale session as early as
possible. Normal call will be rejected when emergency call is still there.
initiating emergency session deletes the current IKE session
ePDG will delete
previous IKE sessions if any present when emergency call is setup
The ePDG does
not consider HSS provided information to setup a connection, rather uses
locally configured PGW and APN information to setup the PDN connection.
13 Based Emergency APN Support
Use the following
configuration to configure Sending SWm 3GPP AAA IP Address in CSreq.
crypto template crypto_templet_name ikev2-dynamic
ikev2-ikesa emergency keepalive interval keepalive_interval timeout timeout num-retry
requires the below existing CLI for configuring Release 13 Based Emergency APN
Below are the show commands outputs added as part of Release 13
Emergency PDN Support:
LTE Emergency Profile: <name>/None
show epdg-service statistics
Non UICC Sessions: