VoIP: FAQs

What is the typical migration cost?

This depends on a lot of parameters. What type of system would the company be

migrating from? What is their end goal in terms of functionality? What is their

required margin of fault tolerance? What are the organization’s growth plans?

In fact, a typical migration cost can only be worked out on case to case basis.

A small organization coming from a legacy system with poor architecture and

possibly poor IT support could cost significantly more than a very large

migration from a standardized network with existing high QoS infrastructure.

Does the migration cost justify the benefits?

We would not recommend that anybody rip out the existing PBXs at this time.

So in other words, no we don’t think the benefits justify the cost. In fact an

enterprise should plan installing VoIP as new offices come online or when

upgrading existing PBXs.

What kind of an infrastructure will be required for running voice services

over packet networks?

There are three things to look for when evaluating your infrastructure. One,

does your network have multiple paths between most switches? Two, do your

routers and switches have power back-up? Three, are all the IP phones connected

to switched segments? In other words, the network architecture should be of open

standard and policy enabled. It should be capable of prioritizing and queuing

packets using differentiated services (Diffserve) architecture with very low

latency and packet loss. While experts have found out that humans can endure

latency of only up to 250 milliseconds, the maximum packet loss an enterprise

the telephone solution can tolerate is 10%.

What is the best architecture option–the IP-based PBX, the IP-only

architecture or the hybrid system?

For most large enterprises that already have PBX but want to implement VoIP,

the best option is an IP-based PBX. This will minimize the risk and give them

some investment protection. If an enterprise is setting up a new site, IP-only

solutions are most suited.

One of the main questions to asks is does the system supports the features

you need. As most of the IP-only systems today lack some of the PBX features, a

hybrid system is the best choice.