SIP and networks
How many SIP trunks do you need?
Channels are sized against overlapping calls, not headcount. The arithmetic, a worked example, and what one channel too few actually costs you.
· 6 min read
VoIP & networks
SIP and networks
SIP trunking, SIP ALG, bandwidth and quality of service: the plumbing under a phone system, and what breaks it.
Articles
SIP and networks
Network settings that break VoIP audio
One-way audio has a direction, and the direction names the fault. NAT timeouts, symmetric RTP, double NAT and QoS, in the order worth checking them.
· 7 min read
SIP and networks
SIP ALG: why to turn it off
SIP ALG rewrites the addresses inside your call setup, and it usually gets some of them wrong. What it does, what it breaks, and where the setting hides.
· 7 min read
SIP and networks
What happens when your internet drops
The call goes silent and nothing is told. What a phone system can and cannot do about an outage, how forward on failure works, and what to arrange beforehand.
· 7 min read
SIP and networks
What is SIP trunking, and do you need it?
A SIP trunk links a phone system you own to the public network. What it replaced, how channels are counted, and why most small offices never buy one.
· 7 min read
SIP and networks
Why your VoIP phone will not register
Credentials, then the network path, then the firewall, then the router's SIP helper, then DNS. What each failure looks like, and how to tell them apart quickly.
· 8 min read
