Archive for the ‘Voice over IP’ Category

SIP – Example Simple Two-Party Call Flow

August 14th, 2012 No comments


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SIP is defined by RFC 2543 and is used for multimedia call session setup and control over IP networks. Read more…

Categories: Voice over IP Tags: ,

Configuring Elastix SIP Trunk to Sipgate

January 16th, 2012 No comments

Another aide-memoir, these are the setting required to enable a sipgate account (and PSTN number) to connect to a phone registered to your Elastix / Asterisk PBX:
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Categories: Voice over IP Tags: ,

Asterisk Security Threats and Best Practices

December 28th, 2011 No comments

Attacks on Asterisk-based telephony systems are not uncommon. This video explains how to mitigate some attack vectors:
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Categories: Security, Voice over IP Tags:

Asterisk CLI Commands

December 30th, 2010 No comments

Another aide-memoir reproduced from  Asterisk provides Voicemail services with Directory, Call Conferencing, Interactive Voice Response, Call Queuing. It has support for three-way calling, caller ID services, ADSI, IAX, SIP, H.323 (as both client and gateway), MGCP (call manager only) and SCCP/Skinny. SEE ALSO:  The Asterisk Book

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Categories: Voice over IP Tags: ,

Case Study – Largest VoIP Deployment in the Industry (Cisco’s own VoIP Network)

May 21st, 2010 No comments

This PDF describes the deployment strategy in detail, including planning, deployment and lessons learned.  A very useful document if you are planning a large VoIP upgrade or installation.  VIEW PDF

Categories: Network Design, Voice over IP Tags:

Trunk to Asterisk from Cisco Call Manager Express

May 14th, 2010 No comments

This configuration enables a trunk between an Asterisk Open Source PBX and Cisco Unified Call Manager Express: Read more…

Categories: Voice over IP Tags: ,

SIP – Communicating Between Domains

May 14th, 2010 No comments

Another Aide-Memoir: SIP User Agents in different domains  – session establishment (also uses location server): Read more…

Categories: Voice over IP Tags: ,

Testing VoIP using “Fun Numbers”

May 13th, 2010 No comments

Fun numbers are free (no cost) numbers you can call to either test your connection or get several services. The connections to these numbers are usually free of charge, as the “lines” are using the internet to transfer your voice between you and the service. Read more…

Categories: Voice over IP Tags: , ,

Voice – Packet Overhead

April 27th, 2010 No comments

Planning for Voice over IP requires an understanding of the various headers added when transporting packetised voice, espcially over an IPSec VPN: Read more…

Categories: Network Design, QoS, Voice over IP Tags: , ,