Synchronous Ethernet Overview - Cisco ASR1000-RP1 - ASR 1000 Series Route Processor 1 Router Software Configuration Manual

Synchronous Ethernet Support
Synchronous Ethernet (SyncE) defined by the Telecommunication Standardization Sector (ITU-T)
standards, such as G.8261 and G.8262, leverages the PHY layer of the Ethernet to transmit clock
information to the remote sites.
This chapter covers the following topics:
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Synchronous Ethernet Overview

SyncE over Ethernet provides a cost-effective alternative to the Synchronous Optical Networking
(SONET) networks. For SyncE to work, each network element along the synchronization path must
support SyncE. To implement SyncE, the bit clock of the Ethernet is aligned to a reliable clock that is
traceable to the Primary Reference Clock (PRC).
Cisco ASR 1000 Series Routers have a dedicated external interface known as BITs interface to recover
clock from a Synchronization Supply Unit (SSU). ASR 1000 router uses this clock for SyncE. The BITS
interface supports E1(European SSUs) and T1 (American BITS) framing.
Table 10-1
Table 10-1
BITS or SSU Port Support
Matrix
T1
T1
E1
E1
E1
E1
2048 kHz
OL-16506-10
Synchronous Ethernet Overview
Synchronization Status Message and Ethernet Synchronization Messaging Channel
Restrictions and Usage Guidelines
Configuring Synchronous Ethernet
lists the framing modes for a BITS port on a Cisco ASR 1000 Series Router:
Framing Modes for a BITS Port on a Cisco ASR 1000 Series Router
Cisco ASR 1000 Series Aggregation Services Routers Software Configuration Guide
C H A P T E R
Framing Modes
Supported
T1 ESF
T1 SF
E1 CRC4
E1 FAS
E1 CAS
E1 CAS CRC4
2048 kHz
10
SSM or QL
Support Tx Port
No No
No No
No No
No No
No No
No No
No No
Rx Port
Yes
Yes
Yes
Yes
Yes
Yes
Yes
10-1