QUOTE:
All the 22 DVRs are on the same LAN, and each DVR has up to 8 cameras, so we want to connect all the 22 DVRs together to view them as 1 on WAN.
Thank you
Well for a start, if they are all the same make/model they will all have the same default IP address, (avtech 760 uses 192.168.1.10) so after reading your manual, you will need to hook up one DVR at a time to the network, log on to it using the default IP address and then change the IP address. once the IP address is changed then do the next one and so on. use IP addresses high up so not to conflict with other network devices.
Note:
If you cannot log onto the first DVR, check that your network is using the same IP range i.e. 192.168.1.***. routers do vary.