Using Synchronous Ethernet Timing For T1/E1 Mda; Clock Source Quality Level Definitions - Nokia 7210 Configuration Manual

7210 SAS-M, T, R6, R12, Mxp, Sx, S Basic System
Configuration Guide
Synchronous Ethernet using fixed copper ports is supported only on the
7210 SAS-T, 7210 SAS-R6, 7210 SAS-R12, 7210 SAS-Sx 1/10GE, 7210 SAS-S 1/
10GE and 7210 SAS-Mxp. The fixed copper ports can be used as a candidate
reference (Master) or for distribution of recovered reference (Slave). If the port is a
fixed copper Ethernet port and in 1000BASE-T mode of operation, there is a
dependency on the 802.3 link timing for the Synchronous Ethernet functionality (refer
to ITU-T G.8262). The 802.3 standard link Master-Slave timing states must align with
the desired direction of Synchronous Ethernet timing flow. When a fixed copper
Ethernet port is specified as an input reference for the node or when it is removed as
an input reference for the node, an 802.3 link auto-negotiation is triggered to ensure
the link timing aligns properly.
The SSM of Synchronous Ethernet uses an Ethernet OAM PDU that uses the slow
protocol subtype. For a complete description of the format and processing, refer to
ITU-T G.8264.
6.5.6.1
Only on 7210 SAS-M and all its variants, the timing recovered from Synchronous
Ethernet is available for use with the T1/E1 MDA. Operators can use a stable
frequency for timing the T1/E1 ports in applications where ACR is not suitable for
use. Refer to the 7210 SAS OS R11.0Rx Software Release Notes for more
information about specific software releases in which this feature is supported.
6.5.6.2
This section describes the clock source quality levels identified for tracking network
timing flow in accordance with the network deployment options defined in
Recommendation G.803 and G.781. The Option I network is developed on the
original European SDH model; Option II network is a network developed on the North
American SONET model.
In addition to the QL values received over SSM of an interface, the standards define
the following additional codes for internal use.
3HE 17358 AAAB TQZZA

Using Synchronous Ethernet Timing for T1/E1 MDA

Clock Source Quality Level Definitions

• QL INVx is generated internally by the system if and when an unallocated SSM
value is received, where x represents the binary value of this SSM. Within the
SR OS, these independent values are assigned as the single value QL-
INVALID.
• QL FAILED is generated internally by the system if and when the terminated
network synchronization distribution trail is in the signal fail state.
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