VOIP monitor useless within a centralised setup ?

 We have an European wide network with a centralized call platform.

Our agents in other countries have a SIP phone that communicates with a centralized Genesys IPMX server ( soon to be upgraded to SIP server ).

The only voice access is here in Belgium, so how am I ever going to measure voip traffic when there is no VOIP IP SLA capable system at my endpoints in the other countries ?