If you use a firewall that limits access from and/or to certain IPs, please whitelist the IP ranges listed below for both TCP and UDP.
|Subnet||Start IP||End IP|
|SIP|| 5060 UDP
|RTP||ANY PORT - UDP|
Do not forget: Disable SIP Application Layer Gateway (SIP ALG).
One last thing to check in the firewall is to allow fragmented packets. If we send packets of more than 1500 bytes, they will be sent in a fragmented way. Not all firewalls allow fragmented packets and this should also be checked.
- Disable SPI (Stateful Packet Inspection).
- Disable Strict Security in the Firewall options.