and investigating network issues related to the Diameter interface, it is
important to filter the subscriber or UE specific Diameter traffic. Any traffic
associated with a particular IMSI can be easily filtered, even without knowing
the Diameter session ID, if the IMSI information is embedded into the Diameter
Session ID AVP. This feature allows the operator to filter the subscriber or UE
specific Diameter traffic.
introduces a new CLI command
mode to embed IMSI into Diameter session ID AVP over the Gx,
Gy, and Gz (Rf) interface.
This feature is
license controlled. Contact your Cisco account representative for information
on how to obtain a license.
How It Works
A new CLI command
has been added under the
mode to enable/disable inclusion of IMSI in Session-Id AVP
for all Diameter sessions associated with that Diameter endpoint. Operators can
enable only the required Diameter endpoints and control the inclusion of IMSI
in the Session-ID AVP. IMSI information is included in the Diameter Session-ID
AVP over the Gx, Gy, and Gz (Rf) interface, if the
is enabled on respective Diameter endpoints.
For emergency call
with "only IMEI", IMSI information is not available for that emergency PDN.
Hence, this IMSI information is not included in Diameter Session-ID at Gx, Gy,
and Gz interface, when
is enabled. Configuring
impacts only new PDN connection and does not have any impact
on existing PDN connection behavior (Gx, Gy, and Gz (Rf)) interface. For
example, if the CLI command to include IMSI is enabled for the Gy Diameter
endpoint after PDN creation. If a new dedicated bearer is created after this
configuration change, then in this case Gy session established for a new
dedicated bearer is not included IMSI in Gy Diameter session ID.
There is no impact
of session manager recovery/ICSR on the session-ID AVP. Session-ID associated
with Gx, Gy, and Gz (Rf) session is recovered transparently (which is
irrespective of latest endpoint configuration). New sessions come up with
session IDs as per the configuration on the newly active chassis.
Following are the known limitations of this feature:
Assuming IMSI information as sensitive information, operator must
consider security aspects before enabling this CLI option.
For an emergency call with "Only IMEI", IMSI information is not
available for the emergency PDN, hence it is not included in the diameter
Session-ID at Gx, Gy, and Gz (Rf) interface.
During ICSR upgrade scenario, it is assumed that the new CLI
option must be enabled only when the upgraded chassis is in stable state and
there exists no chances of ICSR downgrade.
If new CLI is enabled in the newer version of chassis, ICSR
Downgrade is not recommended.
As new CLI option is not available in old software versions, hence
ICSR downgrade is not recommended. Performing ICSR downgrade should have the
following impact on the diameter sessions, which have IMSI, included as part of
Gx and Gy: Existing diameter session (Gx, Gy) should be
downgraded with old format of Session-Id. In that case, both P-GW and PCRF are
out of sync leading to hanging session at P-GW or/and PCRF. Any communication
from PCRF (RAR)/P-GW (CCR-U) can lead to stale session deletion.
Gz (Rf): However, Rf sessions should be recovered properly and
any Rf signaling is sent out to Rf servers properly but responses cannot be
processed as diamproxy cannot parse the new format session id which again puts
Rf sessions into stale state until purged.
Accounting Interim Interval
The following CLI
command has been added under the
endpoint configuration mode to include IMSI in Diameter session-ID
per Diameter endpoint at Gx, Gy, and Gz (Rf). Configuration changes will be
applicable only to new Sessions at Gx, Gy and Rf. Configuration changes will
not have any impact on existing sessions behavior at Gx, Gy, and Rf. For Gy,
multiple Diameter sessions can be initiated per subscriber and the session ID
format setting will bind to the subscriber. The setting will be taken to effect
when the first Diameter session is established and following Gy sub sessions
will keep using the session ID format used in first session.
configurecontextcontext_namediameter endpointendpoint_name[no] session-id include imsiend
session-id: Describes Diameter Session-ID format
include: Includes configured information in Diameter Session-ID
Includes International Mobile Subscriber Identification (IMSI) in Diameter
no: Disables this
feature, that is, IMSI is not included in the Diameter Session-ID, which is the
CLI is disabled, hence IMSI will not be populated in Diameter Session-ID.
sections describe commands available to monitor the feature.