Configuring SAToP Emulation on T1/E1 Interfaces on Circuit Emulation PICs
This configuration example applies to the mobile backhaul application shown in Mobile Backhaul Application.
Setting the Emulation Mode
To set the framing emulation mode, include the framing statement at the [edit chassis fpc fpc-slot pic pic-slot] hierarchy level:
After a PIC is brought online, interfaces are created for the PIC’s available ports according to the PIC type and the framing option used:
- If you include the framing t1 statement (for a T1 Circuit Emulation PIC), 12 CT1 interfaces are created.
- If you include the framing e1 statement (for an E1 Circuit Emulation PIC), 12 CE1 interfaces are created.
 | Note: If you set the framing option incorrectly for the PIC type, the commit operation fails. Circuit emulation PICs with SONET and SDH ports require prior channelization down to T1 or E1 before configuring. Only T1/E1 channels support SAToP encapsulation or SAToP options. Bit error rate test (BERT) patterns with all ones received by T1/E1 interfaces on Circuit Emulation PICs configured for SAToP do not result in alarm indication signal (AIS) defect. As a result, the T1/E1 interfaces remain up. |
Configuring SAToP Emulation on T1/E1 Interfaces
- Setting the Encapsulation Mode
- T1/E1 Loopback Support
- T1 FDL Support
- Setting the SAToP Options
- Pseudowire Interface Configuration
Setting the Encapsulation Mode
T1/E1 channels on circuit emulation PICs can be configured with SAToP encapsulation at the PE router, as follows:
You do not need to configure any cross-connect circuit family because it is automatically created for the above encapsulation.
T1/E1 Loopback Support
Use the CLI to configure remote and local loopback as T1 (CT1) or E1 (CE1). By default, no loopback is configured. See Configuring T1 Loopback Capability and Configuring E1 Loopback Capability.
T1 FDL Support
If T1 is used for SAToP, the T1 facility data-link (FDL) loop is NOT supported on the CT1 interface device because SAToP does not analyze T1 framing bits.
Setting the SAToP Options
You can configure the following SAToP options:
- groups—Specify groups.
- excessive-packet-loss-rate—Set packet loss options.
- idle-pattern—An 8-bit hexadecimal pattern to replace TDM data in a lost packet (from 0 to 255).
- jitter-buffer-auto-adjust—Automatically adjust the jitter buffer.
- jitter-buffer-latency—Number of milliseconds delay in the jitter buffer (from 1 to 1000 milliseconds).
- jitter-buffer-packets—Number of packets in the jitter buffer (from 1 to 64 packets).
- payload-size—Configure the payload size, in bytes (from 32 to 1024 bytes).
- sample-period—Number of milliseconds over which excessive packet loss rate is calculated.
- threshold—Percentile designating the threshold of excessive packet loss rate (from 1 to 100 percent).
The following example shows the SAToP configuration options:
Pseudowire Interface Configuration
Configuration for the TDM pseudowire at the PE uses the existing Layer 2 circuit infrastructure:
After the CE-bound interfaces (for both PEs) are configured with proper encapsulation, payload size, and other parameters, the two PEs try to establish a pseudowire with pseudowire emulation edge-to-edge (PWE3) signaling extensions. The following pseudowire interface configurations are disabled or ignored for TDM pseudowires:
- ignore-encapsulation
- mtu
The supported pseudowire types are:
- 0x0011 Structure-Agnostic E1 over Packet
- 0x0012 Structure-Agnostic T1 (DS1) over Packet
When the local interface parameters match the received parameters, and the pseudowire type and control world bit are equal, the pseudowire is established.
For detailed information about configuring TDM pseudowire, see the Junos VPNs Configuration Guide.
For detailed information about PICs, see the PIC Guide for your router.
