Introduction

The Nortel Multimedia Communications Server (MCS) 5100 is one of the first systems to push SIP to the forefront ahead of its competitors in the voice over IP (VoIP) arena. It takes the best of both worlds from a PBX system and a computer application system and combines them into the system we will be looking at throughout this book. This first chapter provides a high-level overview of what the system is and what it is not, and a look at some of the major services provided by the MCS 5100.

To understand how this system works and how it operates with other systems, you need to have somewhat of an understanding of the SIP Protocol (see Chapter 8). Although the MCS 5100 can also provide and use H.323, most users and enterprise users are moving to SIP due with is complexity compared to H.323. Currently there are a few other major players that are following the lead of Nortel using SIP; for example, Cisco and Microsoft. In the Microsoft LCS and the new version of Call Manager both have gone to a SIP-based presence for their clients.

But Nortel has continued to evolve in front of the competitors by offering more than just a phone and voice mail. It has expanded into other areas of mobility such as personal digital assistants (PDAs) and wireless clients. The ability Nortel has to do SIP to endpoints such as those from Polycom has proven the potential of the MCS 5100 to...