Hello all,
We are testing version 7 of the Phone System here. We have office with internal extensions plus few external extensions.
Internal extensions works perfect. There is very strange issue with external ones.
Assume there are two external extensions. Both are in the same city. Both external extensions have firewalls (routers Linksys WRT54), on both routers no single port is forwarded to phone extensions.
Extension number one is on the same internet provider - cable. Extension number two is on different DSL provider.
Extensions number one has phone Linksys sipura, extensions number two has Linksys PAP2T adapter and regular phone.
Now strange things starts: Extension number one which is on the same cable internet provider works perfect and does not required STUN server !!! It is strange since it is behind the firewall which is completely closed and it still able to send its own EXTERNAL IP to the Phone system's server. Maybe this is because this extension is with the same Internet provider ?
Extension number two, which is on different internet provider require STUN server and NAT enabled, otherwise we have only one way communication. On its firewall also no single port is opened.
When using STUN and NAT there are no problem with second extension except every 30-32 sec call is dropped. But only when this extension is calling to the office. When from office we call to this extension no call drop. No ACK received ... bla bla bla. I understand that I have to open and forward port 5060 both TCP and UDP to second extension's IP probably. But than WHY EXTENSION NUMBER one, which has firewall CLOSED is able to receive ACK from server and does not drop connection ??? I can not understand this at all.
Thank you.
Vlad
We are testing version 7 of the Phone System here. We have office with internal extensions plus few external extensions.
Internal extensions works perfect. There is very strange issue with external ones.
Assume there are two external extensions. Both are in the same city. Both external extensions have firewalls (routers Linksys WRT54), on both routers no single port is forwarded to phone extensions.
Extension number one is on the same internet provider - cable. Extension number two is on different DSL provider.
Extensions number one has phone Linksys sipura, extensions number two has Linksys PAP2T adapter and regular phone.
Now strange things starts: Extension number one which is on the same cable internet provider works perfect and does not required STUN server !!! It is strange since it is behind the firewall which is completely closed and it still able to send its own EXTERNAL IP to the Phone system's server. Maybe this is because this extension is with the same Internet provider ?
Extension number two, which is on different internet provider require STUN server and NAT enabled, otherwise we have only one way communication. On its firewall also no single port is opened.
When using STUN and NAT there are no problem with second extension except every 30-32 sec call is dropped. But only when this extension is calling to the office. When from office we call to this extension no call drop. No ACK received ... bla bla bla. I understand that I have to open and forward port 5060 both TCP and UDP to second extension's IP probably. But than WHY EXTENSION NUMBER one, which has firewall CLOSED is able to receive ACK from server and does not drop connection ??? I can not understand this at all.
Thank you.
Vlad
