Extensions become unreachable

I have a PBX we’ve had for years but recently our system admin has left. We were in the middle of adding a second office on that PBX when that happened. Everything seemed to go fine, but after about 10-15 minutes the phones started becoming unreachable. After 5 or so of them dropped, one would come back and another one of them would become unreachable. So right now it seems to randomly drop the extensions. But while they are in that unreachable state and will not ring on incoming calls, people can make outgoing calls on them. This only happens on the second office. The first one is running fine with no issues, no extensions dropping. Any ideas? I can get whatever logs you’d need to look at. Any help would be appreciated.

Are you using a VPN between the offices?

No vpn, static IP for PBX is on an external number and phones connect straight to it.

Maybe paste the issue of:-

rasterisk -x ‘sip show peers’

when some phones are unreachable.

Here’s the read out for that. The 400s are the extensions I’m having problems with.

110/110 D N A 1037 UNREACHABLE
111 (Unspecified) D N A 0 UNKNOWN
112/112 D N A 1040 OK (28 ms)
113/113 D N A 5060 OK (28 ms)
114 (Unspecified) D N A 0 UNKNOWN
115/115 D N A 1039 OK (6 ms)
140/140 D N A 5060 OK (32 ms)
200/200 D N A 5062 OK (28 ms)
300 (Unspecified) D N A 0 UNKNOWN
401/401 D N A 50224 UNREACHABLE
402/402 D N A 50221 UNREACHABLE
403/403 D N A 50223 UNREACHABLE
404/404 D N A 50857 UNREACHABLE
405/405 D N A 50220 UNREACHABLE
406/406 D N A 50222 UNREACHABLE
407/407 D N A 50306 OK (62 ms)

Look at the port, your router has NAT turned on and the sessions are timing out.

Use a VPN

If it’s not connected across the Internet but on a private circuit turn NAT off on your router.

Will give that a shot, thanks.