Zhone Technologies IMACS Network Device - Manual (Page 90)

Zhone Technologies, Inc. IMACS Product Book, Version 4
March 2001 Page 86
Cell
Site
# 96
Mobile
Base Station
56/64Kbps
CellDAX
DS1
Mobile Switch Office
T1
T1
MDIS
Frame Switch
4 Channelized
DS1s = 96 DS0s
2 Frame Relay DS1s
IMACS
IMACS
Figure 35—Cellular Network Frame Relay Application
Frame Relay Concentration at Hub Sites
In the application shown in Figure 36, a corporation, which serves a wide geographical area through multiple branch
offices, is able to utilize the Frame Relay server’s ability to consolidate and multiplex multiple NX56/64K circuits
into a single high-speed facility. This significantly reduces its access charges from its service provider for its
corporate Frame Relay network. Typical examples include banks, health care providers, technology parks, etc.
The branch offices typically subscribe to a Frame Relay service with a Committed Information Rate (CIR) of
56/64K. At the Head Office/Data Center the traffic is typically from a “farm” of front-end processors, routers and
servers. Without an IMACS+FRS at the Head Office/Data Center, multiple circuits would occupy multiple ports in
the service provider’s switch and would be tariffed for lower individual speeds. With an IMACS+FRS, the multiple
lower speed circuits are consolidated and groomed into a single/few high-speed (Nx64K) circuit. Since the marginal
access charge of Frame Relay is lower at higher speeds, due to economies of scale, this could reduce costs.