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Copyright © 2011, Juniper Networks, Inc. BX7000 Multi-Access Gateway Overview 3
CHAPTER 1: BX7000 Multi-Access Gateway Overview
CHAPTER 1
BX7000 Multi-Access Gateway
Overview
This chapter gives an overview of BX7000 Multi-Access Gateway. It contains the following
sections:
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BX7000 Multi-Access Gateway Overview on page 3
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Gateway System Architecture on page 3
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Hardware Components on page 4
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Advanced Clocking Module on page 13
BX7000 Multi-Access Gateway Overview
The gateway is a mobile backhaul aggregation system that supports both Ethernet and
time-division multiplexing (TDM) interfaces. It aggregates 2G TDM and 3G Asynchronous Transfer
Mode (ATM) cellular traffic streams (voice, audio, and video) from multiple cell sites and carries
the streams towards the base station controller (BSC) or radio network controller (RNC) over
emulated circuits. It allows simultaneous delivery of real-time and delay-tolerant traffic, enhancing
bandwidth utilization. In addition, it performs IPv4 forwarding.
Gateway System Architecture
The gateway can be deployed at the cell sites (base transceiver station (BTS)) and access or
aggregation hub for the cell sites. The gateway architecture separates the control operations from
the packet forwarding operations, which helps to eliminate processing and traffic bottlenecks.
The gateway architecture consists of two parts:
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Packet processor—Performs route lookups, packet forwarding, and interworking functions for
pseudowire aggregations
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Host processor—Provides Layer 3 routing services and network management
Though there are two logical parts, physically they are packaged in a single integrated chip, using
an internal fabric to communicate with each other. The packet processor and the host processor
are realized using an off-the-shelf network processor. See Figure 1 on page 4 for an overview of the
gateway architecture.