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    ACX Series Universal Access Router Overview

    The ACX Series Universal Access Router is principally designed to provide superior management for rapid provisioning to the access network. The ACX Series routers support rich Gigabit Ethernet and 10-Gigabit Ethernet capabilities for uplink, along with support for legacy interfaces and Gigabit Ethernet interfaces for radio and NodeB connectivity in a compact form factor that is environmentally hardened and passively cooled. Seamless, end-to-end MPLS can be used to address legacy and emerging requirements to provide the foundation for a converged network that utilizes the same mobile backhaul infrastructure for business or residential services.

    ACX Series Router Architecture

    The ACX Series router is a single-board router with a built-in Routing Engine and one Packet Forwarding Engine that has two “pseudo” Flexible PIC Concentrators (FPC 0 and FPC 1). Because there is no switching fabric, the single Packet Forwarding Engine takes care of both ingress and egress packet forwarding.

    • Routing Engine—Provides Layer 3 routing services and network management.
    • Packet Forwarding Engine—Performs Layer 2 and Layer 3 packet switching, route lookups, and packet forwarding.

    The general architecture for ACX Series routers is shown in Figure 1.

    Figure 1: ACX Series Router Packet Forwarding and Data Flow

    ACX Series Router Packet Forwarding
and Data Flow

    Junos OS

    The ACX Series router is powered by Junos OS, supporting extensive L2 and L3 features, IP/MPLS with traffic engineering, rich network management, fault management, service monitoring and Operation, Administration, and Maintenance (OAM) capabilities, and an open software development kit (SDK) system that allows providers to customize and integrate operations with their own management systems. For a list of related Junos OS documentation, see

    As part of the mobile backhaul, the ACX Series router at the cell site and the MX Series router at the aggregation layer provide comprehensive end-to-end Ethernet, MPLS, and OAM features with the one Junos OS running on both platforms.


    The ACX Series routers support time-division multiplexing (TDM) T1 and E1 interfaces and Gigabit Ethernet (10GbE, 100GbE, 1000GbE copper, and 1GbE and 10GbE fiber) interfaces to support both the legacy and evolution needs of the mobile network. Support for Power over Ethernet Plus (PoE+) at 65 watts per port mitigates the need for additional electrical cabling for microwaves or other access interfaces.

    Mobile Backhaul

    In the mobile backhaul scenario, the ACX Series router is primarily used in the access layer as the cell site router and the MX Series router is used as the edge and aggregation router. As the cell site router, the ACX Series router connects the base station (BS) to the packet network. Several cell site routers can be connected in a ring or hub-and-spoke fashion to the upstream preaggregation and aggregation routers (MX Series routers).

    The ACX Series router meets and often exceeds the key requirements for a cell site router. A one-rack unit (U) tall router, the ACX Series router is compliant with the European Telecommunications Standardization Institute (ETSI) 300, as well as environmentally hardened and passively cooled for easy deployment where space and cooling are limited as at the cell site.

    Timing and synchronization are key elements in cell site router deployment. To deliver the highest quality of experience, the ACX Series router supports multiple high-precision timing options—for example, Synchronous Ethernet, 1588v2, and Precision Time Protocol (PTP).

    Note: ACX Series routers cannot be used as a first hop router.

    Junos Space

    Junos Space is a suite of comprehensive Web-based tools for operational management and administration of Juniper Networks routers, including the ACX Series and MX Series platforms. With the unified Junos Space network management system, network provisioning and operations can be streamlined. Juniper Networks has extended Junos Space with powerful new features designed to address the demanding requirements of mobile backhaul.

    Modified: 2018-01-30