Nortel Communication Server 1000 (CS1K) is a full-featured IP-distributed communications
 system that delivers the benefits of network convergence and collaborative communications to today’s increasingly “Virtual” Enterprise  environments. 

CS1K  is a highly scalable communications platform with built-in reliability and survivability
 that can be distributed across IP LAN and WAN infrastructures.  Core system components include three primary elements:

• CS 1000 Call Servers provide reliable call and connection management service. It controls
   the system software and is capable of supporting up to 15,000 IP clients per server, as well
   as supporting geographically redundant configurations  to ensure business continuity.

• Signaling Servers perform important call control services such as registration of IP
   terminals, IP address translation and bandwidth control. It streamlines the network dialing
   plan and simplifies the scalability and management of CS1K networks.

•  Enterprise Media Gateways support a complete range of analog and digital line and trunk
   interfaces across LAN or WAN infrastructures.

CS 1000 supports a broad portfolio of business-critical applications including Contact Center, CallPilot unified messaging, SIP-based multimedia services i.e. Multimedia Communication Server 5100 rich media services, and integrated services such as Nortel Integrated Personal Call Director and Nortel Integrated Recorded Announcement, centralized management, and over 650 world-class telephony features designed  to keep your enterprise competitive.