Recovery techniques in mobile networks
A technique for protecting location information of a subscriber in a mobile network is disclosed. A User Mobility Server (UMS) receives a first query from a first call state control function (CSCF). The UMS transmits a call setup and a subscriber identity to a servicing-call state control function (S-CSCF). The S-CSCF may have no record of the subscriber identity due to a restart are some other event. The UMS receives a second query from the S-CSCF based in part of the subscriber identity. The UMS transmits a home address of a mobile station to the S-CSCF. The UMS may also transmit a profile download to the S-CSCF.
1. A method comprising:
receiving a call setup request including a subscriber identity and a dialed alias for a subscriber at a serving-call state control function (S-CSCF) for call registration after the S-CSCF crashes and restarts;
sending a route request from the S-CSCF to a user mobility server (UMS) to trigger a profile download including the home address of the subscriber;
receiving the home address of the subscriber at the S-CSCF from the UMS to facilitate communication from the S-CSCF to the home address; and
sending the call setup request from the S-CSCF to a home agent at the home address of the subscriber to establish a call with a mobile station.
2. The method of claim 1 , wherein the call setup request includes a subscriber identity associated with the subscriber.
3. The method of claim 2 , wherein the sending a route request comprises querying the UMS based on the subscriber identity.
4. The method of claim 1 , wherein the sending the call setup request comprises sending the call setup request to a care of address of the subscriber.
5. The method of claim 1 , wherein receiving the home address of the subscriber and the sending the call setup request are performed only if information about the S-CSCF stored in the UMS is valid.
6. The method of claim 1 , further comprising forwarding the call setup request to a care of address of the subscriber.
7. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising:
instructions for receiving a call setup request including a subscriber identity and a dialed alias for a subscriber at a serving-call state control function (S-CSCF) for call registration after the S-CSCF crashes and restarts;
instructions for sending a route request from the S-CSCF to a user mobility server (UMS) to trigger a profile download including the home address of the subscriber;
instructions for receiving the home address of the subscriber at the S-CSCF from the UMS to facilitate communication from the S-CSCF to the home address; and
instructions for sending the call setup request from the S-CSCF to a home agent at the home address of the subscriber to establish a call with a mobile station.
8. The non-transitory computer-readable medium of claim 7 , wherein the call setup request includes a subscriber identity associated with the subscriber.
9. The non-transitory computer-readable medium of claim 8 , wherein the instructions for sending a route request comprises instructions for querying the UMS based on the subscriber identity.
10. The non-transitory computer-readable medium of claim 7 , wherein the instructions for sending the call setup request comprises instructions for sending the call setup request to a care of address of the subscriber.
11. The non-transitory computer-readable medium of claim 7 , wherein instructions for receiving the home address of the subscriber and instructions for sending the call setup request are performed only if information about the S-CSCF stored in the UMS is valid.
12. The non-transitory computer-readable medium of claim 7 , further comprising instructions for forwarding the call setup request to a care of address of the subscriber.
13. A system comprising:
an interrogating-call state control function (I-CSCF) configured to:
receive a call for a subscriber;
send a first route request to a user mobility server (UMS);
receive an address of a server-call state control function (S-CSCF) from the UMS; and
send a call setup request including a subscriber identity and a dialed alias to the S-CSCF for call registration after the S-CSCF crashes and restarts; and
the S-CSCF configured to:
receive the call setup request from the I-CSCF;
send a second route request to the UMS to trigger a profile download including the home address of the subscriber;
receive the home address of the subscriber from the UMS to facilitate communication from the S-CSCF to the home address; and
send the call setup request to a home agent at the home address of the subscriber to establish a call with a mobile station.
14. The system of claim 13 , wherein the I-CSCF is configured to receive the address of the S-CSCF and to send the call setup request to the S-CSCF only if information about the S-CSCF stored in the UMS is valid.
15. The system of claim 13 , wherein the S-CSCF is further configured to send the call setup request to a care of address of the subscriber.
16. The system of claim 13 , further comprising the home agent, wherein the home agent is configured to receive the call setup request from the S-CSCF and forward the call setup request to a care of address of the subscriber.
17. The system of claim 13 , wherein the call setup request includes the identity of the subscriber.
18. The system of claim 17 , wherein the S-CSCF is further configured to query the UMS based on the identity of the subscriber.