Please i will like to know which quintum product i can use to do a voip between two office which are about 1km apart.The two office are already linked together using a wireless radio.The offices are not connected to the internet.
Go to a PC on one end of the wireless link.
Ping another computer or device on the remote end.
If you have a delay of less than 500 ms round trip, and around 120 kbs of available bandwith, you could use any VOIP product that it is out there up to three or four channels.
I have done VOIP with DSL links that carry only 64 kb of data, with excelent quality.
As Mike pointed, one of the easiest options may be a Quintum, or a Sipura if all what you wanted is one or two phone lines across the link.
Another thing you need to consider is if the voice and data are transmitted via the same wireless link between two offices, the voice traffic should be configured to have higher priority than data traffice in order to get better voice quality.