SIP protocol defines several messages: INVITE: inviting user to call BYE: terminating connection between two end points ACK: reliable exchange of invitation messages OPTIONS: get information about capabilities of call REGISTER: passes user location information to SIP registration server CANCEL: terminates search for user
SIP Components
User Agents: End system acting on behalf of user e.g. client & server. Initiates SIP request & server receives requests and returns responses on behalf of user. Network Servers: Three types available: Registration server – receives client location updates. Proxy server – forwards receiving request to next-hop server. Redirect server Continue Reading
SIP Functions
SIP has following functions: User Location: determination of end system to use for communications Call Setup: ringing & establishing call parameters by both called and calling parties User Availability: determination of willingness of called party to engage in communications User Capabilities: determination of media and media parameters to use Call Continue Reading
Session Initiation Protocol (SIP)
Distributed architecture for creating, modifying and terminating sessions with one or more participants. Controls communications sessions. Standardised under IETF. Covers video conferencing, audio conferencing and one-to-one telephone calls. Stack independent, usually run over TCP or UDP. Uses request/response model similar to HTTP – client sends a request and gets a Continue Reading
H.323
ITU-T’s (International Telecommunications Union) standard – vendors need to comply to supply VoIP. Encompasses point to point communications & multipoint conferences. Consists of four components: Terminals Endpoint host systems providing real time, two way comms. Can communicate with another H.323 terminal, H.323 gateway or MCU. Gateways Endpoint providing communication between Continue Reading
Current VoIP Standard
Carrying mechanism is Internet Protocol (IP). Protocol issues around establishing and managing connection. Different protocols available for VoIP.
Installing and setting up Jenkins
Previously, we saw how to install UnxUtils to ensure the Jenkins works correctly on a Windows machine. Here we will look at installing and setting up Jenkins. Browse to the Jenkins website, https://jenkins.io/download/, and click the red Download Jenkins button at the top. Then choose either the LTS or Weekly Continue Reading
Installing UnxUtils on Windows
This is only a short post covering the installation of UnxUtils. I previously covered installing Git and following this post will be how to install and configure Jenkins. Jenkins requires some Unix utilities to work so it is advised to install UnxUtils which can be downloaded from https://sourceforge.net/projects/unxutils/. Once downloaded, Continue Reading
Install Git binaries on Windows
Steps to install the Git binaries on a Windows operating system, in this case Windows 8.1. Browse to https://git-scm.com/downloads and download the appropriate version for your operating system. Click through the licence agreement. Select the folder to install Git to. Deselect “Associate .sh files to be run with Bash” as Continue Reading
C# console app to test return codes
To help test a larger piece of work, I needed a small application that I could pass a return code to that would then simply pass it back. This app would simulate TestExecute so that I can then write some Powershell to work with the return code locally rather than Continue Reading