PRELIMINARY
MARCH 2007
METROXS
REV. P1.0.0
INDUSTRY-FIRST, 5G MULTI-SERVICE ACCESS PLATFORM
GENERAL DESCRIPTION
MetroXS is a complete carrier class 5G multi-service
access reference design that achieves Ethernet &
Resilient Packet Ring (RPR) transport over SONET/
SDH networks. MetroXS is composed of several
market-proven Exar devices: the EXtendAR 48
(XRT95L53) multi-protocol framer, and Exar's OC-48/
STM-16 SONET/SDH PHY (XRT91L80), plus a
channelized 5G Resilient Packet Ring (RPR) MAC,
and 4 GE/24 FE port Ethernet aggregator. In addition,
MetroXS includes Exar's unified software API
structure enabling system vendors to port their
innovative applications on this platform with ease.
The hardware supports point-to-point or ring network
configuration for the efficient and cost effective
transport of packet data. The data path of processing
elements is defined by a MPoS mapper (the
XRT95L53), a 5G BW RPR-MAC, and a 4-port triple-
rate Ethernet aggregation device. The RPR-MAC
east-side client port is sourced from the Ethernet
aggregator while the un-occupied client port may be
sourced from a third party network processor. The
configuration and control of these data-path
processing elements is performed with an MPC866
SBC hosting embedded Linux 2.6.
The MetroXS software comprises of a suite of
embedded Linux 2.6 low-level device drivers and OS
transparent API for configuration and control of the
data-path. The stacked architecture lends itself for
easy portability of the device drivers and API across
other OS platforms. A PC hosted GUI client
communicates over a 10/100Base-Tx link with the
MetroXS CLI shim layer over the API. The software
suite also supports a diagnostic back-door serial port
during bring-up and debug for future system level
enhancements.
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Software:
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Full suite of software:
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Embedded Linux 2.6 Low level drivers
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API for configuring and controlling Client, RMAC
& Transport
Optional higher layer software to implement a full-
featured RPR system
Highly portable software
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Platform independent API
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OS adaptation layer features
FEATURES
CLIENT SIDE FEATURES
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4 10/100/1000 Base-Tx copper ports
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IEEE 802.3x Flow control including jumbo frames
IEEE 802.1p Class of service, priority protocols
IEEE 802.3ad link aggregation
IEEE 802.1ad VLAN Stacking
Flexible BW Oversubscription up to 4:1 using
MDRR scheduling algorithm
Class of Service, CoS per port identified by
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IEEE 802.1Q VLAN tagging
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IEEE 802.1p with 8 queues per port
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IP DSCP field
Port based ingress traffic policing using TRTCM with
a granularity of 64Kbps
WRED based scheduling algorithm per queue
Port-based egress traffic shaping in 64Kbps steps
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Traffic Engineering & QoS
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Extensive RMON statistics
TRANSPORT FEATURES
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Supports 2xOC-48 SONET/SDH rings
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Sub 50ms of failure recovery
PDUs:
ATM,
BENEFITS
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Best of SONET and Ethernet:
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Efficient
transport for multi-protocol
Ethernet, LAPS, PPP, HDLC, GFP-F
bandwidth provisioning using VCAT/LCAS
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Compliant to G.7042 next-gen SONET/SDH for dynamic
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Support
for GR-253 compliant alarms and performance
monitoring RPR FEATURES
Fair access to ring bandwidth
Guaranteed BW allocation to high priority traffic
50 ms ring protection
Optimized and cost-effective for data/cell based
traffic
TDM services with flexible and dynamic provisioning
Efficient transport of PDU traffic over NG SONET/
SDH
MEF E-Line Services
MEF E-LAN services
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Flexible architecture supports multiple services:
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Compliant to IEEE 802.17
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RPR node Topology Database, 256 entries
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Supports Steering, and ringlet selection
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Supports 4 Class of Service
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Class A0 (guaranteed bandwidth) & A1
Class B: B-CIR and B-EIR
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Supports rate limiting of Class A, B-CIR, B-EIR, C
Exar
Corporation 48720 Kato Road, Fremont CA, 94538
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(510) 668-7000
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FAX (510) 668-7017
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www.exar.com
EXAR [ EXAR CORPORATION ]
