We have 3 offices located in dubai,london and HQ in USa
We want to implement VOip between sites
Already Equip With
1.Cisco 3600 series VOIP gateways
2.ISDN PRI on both HQ usa & london sites
3.PBX on each site
4.In dubai we have sDSL
5. We have call manager but dont have gate keeper can we use call manager instead of a cisco gatekeep dont know functionaly of gate keep.
6. or we have to purchase cisco gatekeeper .
7. CISCO iP PHONE