Cambium Networks PTP 820 Series User Manual page 975

Chapter 21: TDM Services and Interfaces (CLI)
root> ethernet service add type mp sid 970 admin operational evc-id PW-
Slot12_EVC-70
root> ethernet service sid 970
service[970]>
service[970]> sp add sp-type snp int-type s-tag spid 1 group rp3 vlan
4070 sp-name PWtoRadio_SP4070-1
service[970]> sp add sp-type sap int-type dot1q spid 2 interface pwe slot
1 port 1 vlan 4070 sp-name PWtoRadio_SP4070-1
service[970]> exit
Configuring Pseudowire Path Protection and Dual Homing
(CLI)
Pseudowire path protection enables the operator to define two separate network paths for a single TDM service.
Two different kinds of path protection are available, each suitable for a different network topology:
•
1:1 Pseudowire path protection is suitable for ring networks that consist entirely of PTP 820G and/or PTP
820G and/ or PTP 820F elements with two end-point interfaces for the TDM trail.
•
1+1 Dual Homing Pseudowire path protection is suitable for networks in which the PTP 820G and/or PTP 820F
elements are set up as a chain connected to the third party networks at two different sites. The ring is closed
on one side by the PTP 820G and/or PTP 820F elements, and on the other by third party equipment supporting
SNCP. In this case, there are three end-point interfaces in the PTP 820G and/or PTP 820F section of the
network.
Both types of pseudowire path protection requires the use of SOAM (CFM) at both end-points. The TDM module
sends two data streams to the CPU.
In 1:1 path protection, only the data stream for the active path contains actual traffic. Both data streams contain
continuity messages (CCMs). This enables the TDM module to monitor the status of both paths without doubling
the amount of data being sent over the network. In 1+1 Dual Homing path protection, both data streams contain
actual traffic and CCMs. In both types of path protection, the TDM module determines when a switchover is
necessary based on the monitored network status.
In order to achieve path protection, different provisioning should be made for the Ethernet service corresponding
to each of the two data streams. In order to do this, it is recommended to map the corresponding Ethernet
services to MSTP instance number 4095, which is meant for Traffic Engineering (ports are always forwarding) and
to map the two different transport VLANs over two different paths.
Pseudowire path protection uses CFM to monitor the network paths. Because SOAM (CFM) is configured on the
TDM module level, the TDM module can determine the status of the entire network path, up to and including the
actual TDM interface.
This section describes the CLI commands required to configure CFM and tunnel groups, which are basic
components of a pseudowire path protection configuration. This is followed by a sample configuration, which
illustrates how to perform all the steps required to configure a TDM service with path protection.
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Configuring TDM Pseudowire Services (CLI)