Voice over Internet Protocol (VoIP) Training and Development
IP Network Multimedia PC Initially, PC to PC voice calls over the Internet PSTN Gateway PSTN Gateway Public Switched Telephone Network Gateways allow PCs to also reach phones …or phones to reach phones IP Telephony Model
Why VoIP ? Allows voice to be an IP Application Converged Networks Voice, Video & Data over an IP network Monetary Savings
Functional Elements In IP-Telephony networks, following functional elements are mostly found. Media Gateway Media Gateway Controller Signaling Gateway
Media Gateway Media Gateway performs functions like Physical T1/E1 facility termination Voice Packetization Voice Compression using ITU recommendations G.711,G and G.729 etc
Media Gateway Controller (MGC) A media gateway controller is the overall controller of the system. Media Gateways receives commands from the media gateway controller which define their operations. MGC performs core functions like: Address Resolution Call Routing Resource Management Call Detail Record (CDR) Generation A media gateway controller is also known as a Soft Switch
Signaling Gateway (SG) Signaling gateway transfers signaling information between PSTN node and Media gateway controller (MGC)
Media Gateway Media Gateway Controller Signaling Gateway May be separate physical devices or Integrated in any combination e.g. SG/MG functions Implemented in one unit
IP Telephony Model SG PSTN Node PSTN Node SG SS7 MG PSTN Trunks PSTN Trunks MGC SS7 over IP RTP / UDP / IP MGCP / H.248 IP Network