You have many questions on A400 and SIP. Here are the answers;
1. No, you cannot have both H323 and SIP working at the same time in the A400. There is not enough memory in the older, like A400, units to support both. In the Generation 2 units, you can have both working at the same time, but only for recieving calls from IP. You would need to pick 1 for sending calls to IP.
2. As always, you should go to Quintum’s web site under the support pages and you will find all the information you need to know how to upgrade your unit.
3. As long as the unit is not reset after the connection is lost, then it should be ok and you can resume your upgrade. If the unit resets after the lost connection, but before you finish the upgrade, the system will be locked up and you will need to perform a system recovery.
4. They are different parts of the software that the tenor uses to run. If you read the release notes for each version, it will tell you which software needs to be upgraded. Also, in the directions for upgrading your unit, it should describe the files somewhat.
5. There is a different system software. Again, review the release notes on Quintum’s web site.
6. For the older units, like A400, the SIP software is only beta version. Not full version and I hear that there are problems. Even on the newer units, generation 2 units, SIP is not 100%. Personally, I believe that H323 is much more stable.