VoIP vs. TDM

It is my personal opinion that the long help idea that a VoIP station is easier to manage than a TDM station is a complete farce. I would personally go so far as to say that VoIP technology has introduced a much more complicated administration challenge.

A benefit that VoIP technology has brought to the industry, however, is that it has transitioned the administration onus from a separate, telecom department to the IT department in most cases. IT managers tend to hold vendors to a much higher degree of accountability when it comes to management software packages. If there was any benefit to the transition, it is that telecom vendors were forced to enhance their management platforms to meet the needs of the IT administrator.

VoIP management has introduced a number of issues that were never a problem or only a limited issue with TDM technology.

1. Security

Security challenges surrounding VoIP not only mandate an increase in administration cost, but they also tend to add overall cost in terms of need for added software and equipment to solve the problems.

• Voice path vulnerability when on LAN
• Denial of Service attacks
• Computer Viruses
• Password protection
• Toll fraud
• Spoofing
• SIP Attacks
• Sniffing

TDM technology did not succumb to these challenges. The very simple and segmented nature of TDM was inherently secure in its own right.

2.Voice Quality

VoIP technology has introduced new challenges as it relates to Voice Quality. TDM technology was not prone to deliver poor voice quality, whereas the voice quality of VoIP technology lives at the mercy of the network performance. Any number of different events can have a negative impact on the voice quality of an IP call.

3.Network Configuration Deployment

VoIP technology is much more complicated to deploy than TDM technology. The plethora of network configurations necessary for VoIP can complicate the deployment of the end-points greatly. Configurations must be made to the DHCP servers to accommodate the new devices, new network subnets or vlans must be created to allow for the new devices and a detailed network analysis must be performed to ensure that the infrastructure can support the technology.

4.Power

Because IP devices are locally powered, they are prone to be susceptible to power failure. TDM devices were powered by the PBX itself which would typically have multiple power redundancy options.

5.E911

911 support for VoIP devices has created a great deal of complication. Because of the geographically agnostic and mobile nature of VoIP, it has become increasingly difficult to pinpoint the locations of these devices. TDM, on the other hand, was a hardwired connection to the switch. It's not to say that a TDM device never moved, rather, it's that the telecom manager always knew when it happened and where it went and could make the necessary updates to the database.

It's not that I think that VoIP technology does not have it's place in the future of telecom, it's more that I feel like this technology has not yet matured to the point that managing it is as easy as managing a TDM device.

Different Voice System manufactures are approaching management of VoIP in different ways. NEC, for instance, is addressing each management challenge individuals to try and solve them independently. Given some time, I believe that VoIP might eventually be more simple to manage than TDM. Today, however, the technology has not yet reached that point.

I welcome comments and opinions...

Regards,
-Greg