This entails:
* Adding S1AP paging messaging to the MME.
* Adding the Downlink Data Notification, Donlink Data Notification Acknoledgment, and Downlink Data Notification Failure Messages.
* Adding the logic at the GTP-U to detect that Downlink Data notification needs to be sent.
* Proper handling of the new GTP-C messages at the MME GTPC and SPGW GTPC classes
* Add queuing mechanisms at the GTP-U while waiting for paging response. Queue is flushed when paging fails (timeout or other).
* Make sure eNB's SCTP information is properly stored.
* Make sure UE's GUTI information is properly stored.
* Adding timer creation at NAS using timerfd_create
* Adding the ability to add and remove the timer file descriptor to the MME main select loop
* Adding the ability to the MME for the NAS to check if a timer is running
* Adding the timer expiry handling functionality at the MME
* added config option for tun dev names vs fixed names added config option for M1-U interface addr
* Added options to sgi_mb tun name.
* Added some comments to mbms.conf.example
* Added some comments to example configs to explain the new values.
Pedro Alvarez