Legacy Adaptation to ATM

Zhone Technologies, Inc.

IMACS Product Book, Version 4

equipment, it can be easily added with minimal costs when the MIS manager wants to collapse parallel ATM and TDM networks into a single ATM network. When an ATM network is installed, typically there is excess bandwidth and port capacity that behooves such a merger of networks. For instance, when an ATM switch is deployed each line card will have multiple ATM ports out of which only one or two may be used for data traffic. The IMACS w/ ATM server can be connected to the unused port(s) thereby consolidating other legacy traffic on to the ATM network. This results in significant cost savings for the customer since there is only one as opposed to two networks to be managed.

•Provides DSO granularity for virtual circuit input. By providing DS0 granularity, the ATM server is able to direct individual lower speed voice and data circuits to unique destinations through out the ATM network. This is accomplished without “burning up” multiple physical ports on the ATM switches, which are expensive. The ATM server’s highly efficient and cost-effective aggregation of lower speed CBR and VBR virtual circuits makes this possible.

•Supports constant and variable bit rate adaptation. By supporting constant and variable bit rate services, the ATM server tailors the adaptation to best suit application requirements for quality of service (QoS). E.g., typically voice and video applications require constant guaranteed bandwidth and stringent delay constraint and are modeled as CBR traffic. Data, compressed voice and compressed video are amenable to variations in bandwidth and delay requirements and are modeled as VBR traffic.

•Manageability via SNMP and TELNET. SNMP and TELNET manageability eliminates need for a separate IMACS network management package. The IMACS and its components can be managed from the same existing network management device that manages the ATM backbone and other devices.

The ATM server is deployed in the following application scenarios to provide a very cost-efficient and high-quality ATM service to the end-users:

•Interactive Distance Learning/Tele-Medicine

•Legacy Adaptation to ATM

•Analog PBXs/Key Systems

•Digital PBXs

•Nx56K/64K Data terminal equipment

•Video Codecs

•Transparent LAN Extension

The addition of the ATM Server card further extends the capabilities of the IMACS as a truly integrated access platform by efficiently provisioning a multitude of legacy services for transportation over an ATM network as shown in Figure 37.

There are still many legacy services (PBXs, key systems, video codecs etc.) which need a parallel TDM network to operate since they are not “ATM-ready.” Two parallel networks drive up the cost of installation, operation and maintenance. Since businesses have very significant capital investment in these legacy systems and processes they cannot justifiably be fork lifted and replaced by equivalent “ATM-ready” equipment. Furthermore, when a new ATM campus network is deployed, typically there is excess bandwidth and port capacity that is under utilized. What needs to be added is a cost-effective product for adaptation of all these legacy services to ATM. This would enable connecting a multitude of “non-ATM ready” equipment to the ATM network.

March 2001

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