The Internet and Telecom Acronym Dictionary

Endpoint - an internet telephone interface for computer, devoted VOIP phone, or mobile phone with internet access.

EMG - Enterprise Mobility Gateway.

FMC - Fixed Mobile Convergence

IM - Instant Messaging (text messaging)

iOS - iPhone Operating System, Apple's smartphone operating system

ITSP - Internet Telephony Service Provider

MNO - Mobile Network Operator

MVNO - Mobile Virtual Network Operator

NCC - Network Convergence Gateway

OEM - Original Equipment Manufacturer

Over-the-Top - data applications offered through the basic internet service, or pipe.

PBX - Private Branch eXchange - a telephone exchange service that serves a private company, as opposed
           to a common carrier.

Pipe - Internet cable

Presence - service that detects whether a person is on the telephone or not.

SDK - Software Development Kit

SIP - Session Initiation Protocol, VOIP software for endpoints

SMB - Small to Medium-sized Business

SME - Small to Medium sized Enterprise (business)

SMS - Short Message Service (text messaging)

UC - Unified Communications

URL - Uniform Resource Locator, an internet address

VOIP - Voice Over Internet Protocol

WCC - Wireline Call Continuity.  From counterpath.com "Enables users to move
             a call from their desktop or mobile VOIP phone to another device,
             including their standard mobile phone or smartphone."