creating-a-marketing-campaign-featured

3 Easy tips for people who want to do their own marketing

Start with a good CRM Most companies you deal with every day probably have your personal information saved into their CRM (Customer Relationship Management). These CRMs track everything that companies know about you, including your purchases, your phone calls to the company, and the dates and times you open their emails (if ever). So how [...]

New Website

New website is to be available this weekend.

Firewall types

These are the firewall types: 1. A full cone NAT is one where all requests from the same internal IP address and port are mapped to the same external IP address and port. Any external host can send a packet to the internal host, by sending a packet to the mapped external address. 2. A [...]

RTP – Real Time Transport Protocol

Real time media protocol (RTP) based on UDP for voice. Separate from SIP. SIP establish connection and port numbers for RTP. Not necessary using the same path. Audio Quality depends on codec. ILBC used for google talk and Gizmo, Skype.

SIP registrar and call flow

When a SIP phone starts, it first register itself with the SIP registrar. 1. SIP phone send HTTP request to SIP registrar 2. SIP registrar send SIP phone info to a location database (ip address etc) 3. ACK SIP phone Basic call flow: 1. Invite from a SIP phone to SIP registrar (Proxy) 2. Proxy [...]