Voice and Video Services

Unit: 7 Lesson: 3

i need to watch my employees work from my beach chair in hawaii

We love our telecommunications stack. VoIP, web conferencing, and video teleconferencing (VTC) solutions dominate the modern communications industry. Businesses and social media platforms depend on these services to work. This means upgrading from legacy voice services to IP-based protocols and products.

Private Branch Exchange

Legacy voice services would use the PSTN, which provided a single line for both incoming and outgoing calls. This is NOT suitable for modern needs, where hundreds of voice communication lines can be needed at once, not even considering data transmission lines. Historically, this need would've been filled using a digital trunk line, also called a ~~Time-Division-Multiplexing~~TDM circuit.

A private branch exchange (PBX) is an automated switchboard that provides a single connection point for an entire organization's voice lines. TDM-based PBXs allow for the organization to connect to a telecom provider's network over a digital trunk line, supporting multiple channels. It also allows for the configuration of the organization's internal phone system to direct and route calls to local extensions, provide call waiting, music on hold, voicemail, and other telephony features.

VoIP-Enabled PBX

TDM-based PBXs are being replaced by hybrid and fully IP/VoIP PBXs. VoIP PBXs establish connections between local VoIP endpoints using the local Ethernet network and are also able to route incoming and outgoing calls to external networks.

VoIP-Enabled PBXs can run as a software program running on a Windows Server or Linux server instance, or as part of a unified hardware solution like on a router. There are also cloud-based all-in-one solutions for an organization's VoIP needs (e.g. 3CX). VoIP PBXs are usually placed at the network's edge and protected with a firewall. External routing is facilitated via a network link to a VoIP provider, which also manages inward and outward dialing of voice-based telephone networks.

VoIP Phones

VoIP phones can either be a physical handset or a software client running on a computer. They use VLAN tagging to ensure that the SIP control and the RTP media protocols remain separate from normal traffic on the network. Normally, organizations wire the Ethernet cable from the wall port to the LAN port on the handset (if they're using them), and have the PC connect to a PC port on the handset.

Handsets can use Power over Ethernet to avoid extra cabling configurations. There are also wireless handsets that work over the various 802.11 standards for Wi-Fi.

VoIP phones can be secured in a similar manner to ~~HTTPS,~~HTTPS, using certificates with secure SIP to authenticate endpoints and establish TLS tunnels. Secure SIP can also be configured to generate and use a master key for secure TLS tunneling for RTP and ~~RTCP.~~RTCP.

~~#Netplus~~