Usage Guidelines
With this command, the
APN in the DNS query string, used for querying the GGSN address,
can be appended with additional information, such as
This additional information
allows some customization of the DNS query string to facilitate
selecting a specific (usually local or nearest) GGSN.
For example, roaming
subscribers using a specific APN may want to be directed to a specific
GGSN. This can be achieved by having an operator policy for roaming
subscribers associated with an APN profile that includes a configuration
specifying certain digits, from the MSISDN or geographical information
from the LAC/RAC, be appended to the APN. This is then
used as the DNS query string.
In addition, the operator
must configure appropriate DNS entries to enforce the selection of
the required GGSN. After appending the MSISDN digits to the DNS
query string, the string will have the form:
ni.<digits>.mnc*.mcc*.gprs
After appending the
LAC/RAC information to the DNS query string, the string
will have the form:
<apn_network_id>.racAAAA.lacBBBB.<apn_operator_id>
where the AAAA and
BBBB are Hex-coded digits (less than 4 significant digits and one
or more zero ("0") digits will be inserted to
the left side of the Hex to fill the 4-digit coding).
After appending the
charging characteristic (SCHAR) information, the DNS string will take
the following form:
<apn_network_id>.<profile_index>.<apn_operator_id>
The profile index in
the following example has an integer value 10:
quicknet.com.uk.1010.mnc234.mcc027.gprs
If the RNC-ID information
is configured to be a part of the APN name, and if inclusion of the
profile index of the charging characteristics information is also
enabled before the DNS query is sent, the profile index is included
after the included RNC-ID and the DNS APN name will appear in the
following form:
<apn_network_id>.<rnc_id>.<profile_index>.<apn_operator_id>
Once the DNS extension
is defined, the selected extension is applicable when either the wildcard
APN feature or the default APN feature are configured and used.
The information is appended
to the DNS query and the actual APN string sent to the GGSN will
not be modified in any way.
Examples
A sample MSISDN is '112233445566778' and
a sample APN NI (network identifier) is 'wap98.testnetz.ca'.
The following command instructs the SGSN to create a new APN with
digits pulled from the MSISDN and appended to the APN:
msisdn start-offset 3 end-offset 9
The resulting APN DNS
query string would have appended 7 digits (2233445)to the APN NI
so that it would appear something like wap98.testnetz.ca.2233445.MNC009.MCC262.GPRS
Enable inclusion of geographical
information in the APN string used for the DNS query to locate the
closest GGSN:
In the following example,
the DNS query for a subscriber using RNC 0321 with the profile index
of value 8 would appear as:
quicknet.com.uk.0321.1000.mnc234.mcc027.gprs