How are IP telephone systems different than traditional telephone systems?
Instead of being installed on proprietary software and hardware platforms, Internet Protocol (IP) based systems use the same types of platforms as local area networks (LANs). They transmit voice in data packets similar to envelopes and can operate over the same cabling as organizations’ data networks. In addition, most IP telephone systems are installed on Windows or Linux based servers. These are referred to as server based systems. Older systems use IP cards that fit into traditional telephone systems’ cabinets.

What are advantages of VOIP systems?

• The similarity to administering existing data networks enables staff with expertise in data to administer voice systems.
• Organizations with adequate data networks between sites can save money on voice calls by transmitting packetized voice.
• Remote staff can gain system functionality by logging in from a PC.
• Adjuncts such as call center software and unified messaging should cost less because they don’t need proprietary signaling and hardware to interface with proprietary PBXs.

Are there any causes for concern?
IP based telephone systems are relatively new. Those offered by data vendors such as Cisco don’t offer as many features as traditional PBXs. Stability of the operating system is another issue. For example, some systems operate on Windows 2000, which is less stable than Linux based servers. Also, because they operate on the LAN, they are inoperable during denial of service attacks and other security breaches. In particular, many of the systems are vulnerable to attacks by disgruntled internal employees.

What about voice quality?
Voice quality is acceptable on most systems but data grade cabling is required. Moreover, users need to monitor the level of traffic on their local are networks (LANs). Congestion on LANs from sources such as video, email and voice mail may degrade voice quality.

What does Cisco offer?
Cisco sells AVVID (Architecture for Voice Video and Integrated Data), which they purchased from Intecom subsidiary Selsius and the Unity unified messaging with voicemail system that they bought from Active Voice. Cisco has greatly enhanced its AVVID product.

Who offers IP telephone systems?
Shoreline, Avaya, 3Com, Siemens, Vertical, Alcatel, Mitel, Altigen and Nortel have offerings. Avaya’a recently announced server based Seagull S8700 works on the Linux operating system. They also announced the Sea Hawk S8300 for remote offices. Avaya has software that allows any Pocket PC-based handheld with microphone and headset support to be used as an IP cordless phone.

Cisco vs. Avaya
Cisco currently has the lead in server based VOIP systems. Cisco’s relationship with its installed base is a tremendous benefit. Avaya’s new system has the advantages of a richer set of features and a more stable operating system. Interest in and sales of IP based system is growing. Stability and capabilities of these systems will improve greatly over the next year.