Voice over IP Online Course
Lesson 1 - Voice over IP Overview
D. Telecos and Service Providers
Telephone Companies and Service Providers
- Less expensive for long haul traffic
- Can offer expanded services
- Tie into customer VoIP systems
- Keep installed base
Telcos and VoIP
For telephone companies, VoIP is a major disruptive influence. It requires re-engineering their voice networks and it allows competitors into their market.The telephone companies' voice systems are based on fixed lines with circuit switching. Although voice traffic is already digitized in order to travel over T3 and ATM circuits, these are not packetized. The packet switching services they do offer, X.25 and Frame Relay, are losing their installed base.
Switching over to an IP based network fabric will cause disruption and require an expensive upgrade. On the other hand, an IP based network is more efficient since the traffic of multiple customers can use the lines simultaneously.Realistically , the telephone companies will change over to an IP based infrastructure more because they have to then because they want to. Corporate customers will demand VoIP services, residential customers will be seduced into thinking they should have it and competitors will be offering it.
Figure 7: Converting carriers to VoIP
Converting carriers to VoIP
A superclass softswitch is used to overlay or add VoIP capabilities to the networks of carriers. The superclass softswitch supports multiple core applications on a single platform, including local, long distance and tandem. And it provides these services with the reliability that carriers are expecting. The following carriers or service providers can use a superclass softswitch to convert their core networks to VoIP.- Carriers that currently provide voice services, the traditional telephone companies, typically use a TDM (Time Domain Multiplexing) core infrastructure based on SONET and the DS/T services. Their telephone switches are the DMS series from Nortel, the 5ESS switch from Lucent and the EWSD from Siemens. These systems can overlay VoIP services with a superclass softswitch.
- Cable companies use a technology known as FDM (frequency division multiplexing). VoIP services can be added to these systems, giving cable companies a comprehensive package of services to offer to their customers.
- Service providers that already run an IP or ATM network can also integrate VoIP services by deploying softswitch technology.
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