IES-1248-51V Support Notes
3
Application Notes
How to configure the Voice over IP (VoIP) features
The IES-1248-51V is an IP-based DSLAM that connects ADSL and voice subscribers
to the Internet. It provides 48 aggregated lines of POTS connectivity, designed to
connect the subscriber with the PSTN. Each telephone line interface is a FXS port
connecting to the subscriber’s telephone via copper wire. The analog voice signal
from the subscriber is converted to voice data packets and transmitted towards the
callee across the IP packet-switched network. The IES-1248-51V uses SIP for
network signaling to establish or tear down a voice call. DTMF signals are also
translated into SIP signals (or transmitted in the voice band).
What is VoIP
Traditional voice switching business has long been the mainstay for a relatively small
group of global equipment suppliers. But times has changes, carriers are adopting a
standardized IP Multimedia Subsystem architecture for next-generation networks with
distributed softswitch call control and independent Media Gateways. In addition to the
legacy circuit switch equipment suppliers, the equipment market reshuffles and opens
to new vendors.
Media Gateway is a network element which packetize voice traffic from POTS signals
to IP packets and perform critical voice network features such as echo cancellation,
silence detection and suppression, etc. Softswitch is the one which provides call
control to Media Gateways in a packet voice network.
Through IES-1248-51V, ZyXEL transforms its IP DSLAM portfolio into multi-service
DSLAM and starts to enter the Media Gateway market worldwide.
VoIP is the sending of voice signals over the Internet Protocol. This allows you to
make phone calls and send faxes over the Internet at a fraction of the cost of using
the traditional circuit-switched telephone network.
What is SIP
The Session Initiation Protocol (SIP: RFC 3261) is an ASCII-based, peer-to-peer
protocol designed to provide rendezvous services over the Internet. SIP is an Internet
Engineering Task Force (IETF) specification that was derived from Hypertext Transfer
All contents copyright (c) 2007 ZyXEL Communications Corporation.