On V1 and V2 you need to make sure your address information is correct under the menu Customer. If this is not set correct, you risk to not be able to call to the emergency services, or arrive at the wrong location. Also you need to call out with a valid Belgian Fixed number, which is assigned to the customer (available under Features -> numbers).
On V3 and V5, you need to add a X-header, allowing us to select the correct physical emergency center. We need you to add in the INVITE packet, the header X-postalcode: <postalcode>. The callerid should be a fixed Belgian number, we accept the following number formats: +3222407901, 003222407901, 022407901, 3222407901. Not having this header, will block the call. Having a wrong postalcode in there, will block the call. Having a wrong callerid in there, will block the call.
A SIP INVITE can be e.g.:
INVITE sip:email@example.com:5060 SIP/2.0
From: "+3222407901" <sip:+firstname.lastname@example.org>;tag=XyHQ5jUDQUjBH
You can safely test your setup by calling to 117, which is a testnumber which will tell you the zone it got routed to.
You should also pass us the address information of every customer you set this up for.