Voice over IP

Kamailio
Voice over IP

Kamailio Bytes – UAC – Authenticate Outbound Calls

Using UAC module to authenticate outbound calls where you need to respond to a 401 Unauthorised Response, or a 407 Proxy Authentication required

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EUTRAN
LTE
Mobile Networks
RFCs & Standards
Voice over IP

Diameter and SIP: Registration-Termination-Request / Answer

These posts focus on the use of Diameter and SIP in an IMS / VoLTE context, however these practices can be equally applied to other networks. The Registration-Termination Request / Answer allow a Diameter Client (S-CSCF) to indicate to the HSS (Diameter Server) that it is no longer serving that user and the registration has […]

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Diameter-User-Authorization-Request-Command-Code-300-Packet-Capture
EPC
LTE
Mobile Networks
RFCs & Standards
Voice over IP

Diameter and SIP: User-Authorization-Request/Answer

The Diameter User-Authorization-Request and User-Authorization-Answer commands are used as the first line of authorization of a user and to determine which Serving-CSCF to forward a request to.

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Diameter - Server Assignment Answer - All
EPC
LTE
Mobile Networks
RFCs & Standards
Voice over IP

Diameter and SIP: Server-Assignment-Request/Answer

These posts focus on the use of Diameter and SIP in an IMS / VoLTE context, however these practices can be equally applied to other networks. The Server-Assignment-Request/Answer commands are used so a SIP Server can indicate to a Diameter server that it is serving a subscriber and pull the profile information of the subscriber. […]

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EPC
LTE
Mobile Networks
RFCs & Standards
Voice over IP

Diameter and SIP: Location-Info-Request / Answer

These posts focus on the use of Diameter and SIP in an IMS / VoLTE context, however these practices can be equally applied to other networks. The Location-Information-Request/Answer commands are used so a SIP Server query a Diameter to find which P-CSCF a Subscriber is being served by Basics: The RFC’s definition is actually pretty […]

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GSM
Mobile Networks
Voice over IP

GSM with Osmocom: Call routing in GSM

How call routing in GSM works and it’s application in the Osmocom suite

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EPC
Kamailio
LTE
Software
Voice over IP

Kamailio Proxy-CSCF Pull

My first Pull / Merge in the Kamailio project was to fix the IMS P-CSCF config

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RFCs & Standards
Voice over IP

SIP Register – Lesser Known Features

Some of the lesser used / utilized features of the SIP REGISTER method.

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Kamailio
Voice over IP

Kamailio Bytes – http_client

Using Kamailio to send HTTP requests (POST & GET) to a HTTP server and store the result.

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Kamailio
Voice over IP

Kamailio Bytes – Multiple Kamailio Instances on a Single Box

Running multiple instances of Kamailio on the same server using init.d

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Kamailio
Security
Voice over IP

Kamailio Bytes – SIP over TLS (SIPS)

Using Transport Layer Security (TLS) to protect SIP traffic from modification / manipulation and guarantee message authenticity.

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Kamailio
Voice over IP

Kamailio Bytes – Nightly Releases the Lazy Way

Using apt package manager to install nightly Kamailio builds

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EPC
EUTRAN
LTE
Security
Voice over IP

VoLTE / IMS – P-CSCF Assignment

How the P-CSCF address is assigned to a UE in Protocol Configuration Options (PCO) during bearer establishment.

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Voice over IP

Automated SIP testing with sipcmd

Using sipcmd to test SIP Services from the command line

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