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A collection of 2 posts
SIP with Clearmode on Cisco ISR
ISDN

SIP with Clearmode on Cisco ISR

In this blog post i will try to explain how to configure a Cisco ISR device like the ISR 3825 to use the Clearmode codec to for ISDN traffic over SIP to another device. Clearmode is in simple terms the 64kbit ISDN B channel converted to an RTP stream. Same
20 Sep 2025 1 min read
FreePBX 12 with CLEARMODE support
VOIP

FreePBX 12 with CLEARMODE support

Before i start i have to explain what clearmode is and when you need it. CLEARMODE A phone call is 64Kbps (PCM sampled audio with 8 bit depth * 8000 hz sample rate per direction). A basic rate ISDN connection contain 2 of these channels plus a small channel for signaling.
07 Sep 2025 3 min read
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