Synchronization Infrastructure; Figure 11: Inter-Office Network Timing Infrastructure - Alcatel-Lucent 7710 SR Configuration Manual

Synchronization and Redundancy

Synchronization Infrastructure

Regardless of technology the general synchronization requirements for communication networks
should conform to one of the constructs shown in Figures 1 or 5. These views capture the
hierarchical nature of timing distribution, the terminology and relationships between the
participating elements.
types (in this case stratum) clocks together.
Many Tier 1 carriers are seeking methods to migrate their synchronization infrastructure to a
familiar and manageable model. In order to enable rapid migration of these networks, synchronous
Ethernet may be the easiest to achieve (frequency) synchronization to allow the benefits of an
Ethernet network infrastructure to be realized without any change to the existing TDM network
applications.
Page 194
Figure 11 illustrates the industry limits proposed for chaining particular
st st
1 1
K=10 worst case K=10 worst case
Slave Slave
BITS/SSU BITS/SSU
K-1 K-1 th th
Slave Slave
K K th th
BITS/SSU BITS/SSU

Figure 11: Inter-Office Network Timing Infrastructure

7710 SR OS Basic System Configuration Guide
PRC: g.811 or ST1 clock PRC: g.811 or ST1 clock
N x g.813 or ST3 type N x g.813 or ST3 type
Network Element clocks Network Element clocks
SEC SEC
N=20 max; N N=20 max; N <60 max <60 max
total total
G.812 Transit or ST2 G.812 Transit or ST2
N x g.813 or ST3 type N x g.813 or ST3 type
Network Element clocks Network Element clocks
SEC SEC
G.812 Local or ST3E G.812 Local or ST3E