In many situations the APN provided in the Activation Request is unacceptable. Either it does not match any of the subscribed APNs or could be misspelled, resulting in the SGSN/MME rejecting the Activation Request. The APN Override feature enables the operator to override an incoming APN specified by a subscriber or provided during the APN selection procedure.
There are three methods of performing apn-overriding.
Network Identifier (NI) based overriding
Operator Identifier (OI) based overriding
Charging-characteristic based overriding
A valid license key is required to enable APN Override. Contact your Cisco Account or Support representative for information on how to obtain a license.
MME sends remapped APN to the UE in the ATTACH_ACCEPT or ACTIVATE_DEFAULT_BEARER_REQ messages when APN Remapping feature is enabled. In release 19.5, this behavior is modified so that MME can control to send either the UE requested APN or remapped APN in these messages. This behavior is controlled through adding a new optional keyword orig-apn in the existing apn-remap CLI command in the APN Remap Table configuration mode.
Additional configuration control is provided at the MME service level to reject or accept UE sessions with APN containing non-3GPP standard characters. The following are considered as standard 3GPP characters:
A - Z, a - z (alphabets)
0 – 9 (numeric)
All other characters are considered as non-3GPP standard.
New CLI configuration is also introduced in the APN Remap Table configuration mode to allow remapping of APNs with non-3GPP characters.