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Posted on in voice
If your carrier doesn't allow 10 digit dialing for local numbers, you are probably pretty annoyed that you can't just hit the redial button on those missed calls. It's possible to rewrite these dialed numbers in your phone system, but I wanted to do this on my Cisco 7961 IP …
Posted on in Voice / Telephony
Records a legacy URL-based firmware upgrade method for Linksys and Cisco small-business ATAs.
Posted on in voice
Protocol Basics
Layer: Application
Transport: <acronym title="Transmission Control Protocol">TCP</acronym> or <acronym title="User Datagram Protocol">UDP</acronym>
Port(s): 5060, 5061
RFC(s): 2543, 3261
SIP is by far the most popular protocol used in VoIP communication today. SIP was designed as a …
Posted on in Voice / Telephony
Explains why legacy Asterisk administrators subscribed to release and security-alert announcements, with dated vulnerability context.
Posted on in voice
During a recent project, I was asked to configure a Linksys SPA942 4-Line IP Telephone to work with Asterisk in an medium-sized office environment. Since this phone was going to be one of many used in a corporate environment, I decided I would need one master configuration, and then individual …
Posted on in voice
When using Asterisk and a remote bank of <acronym title="Primary Rate Interface">PRI</acronym>s (or any other form of <acronym title="Public Switched Telephone Network">PSTN</acronym> connectivity for that matter), you may encounter an issue known as hairpinning. Hairpinning describes what happens when a call coming from …
