The following sections describe how to configure
the layers on cOCx/STMx interfaces.
SONET/SDH Configuration Tasks
To configure SONET/SDH on a cOCx/STMx interface:
Select an interface.
Specify a clock source for the interface.
Specify that the mode be SDH, or accept the default mode,
SONET.
(Optional) Assign a text description or an alias to the
interface.
(Optional) Disable processing of SNMP link status information
for the section and line layers of the interface.
Configure the path for the interface.
(Optional—not recommended) Overwrite the automatic
setting for the path signal label (C2) byte.
(Optional) Enable processing of SNMP link status information
for the path layer of the interface.
(Optional) Configure the router to use remote defect indications
(RDIs) at the path layer to determine the operational status of a
path.
(MPLS fast reroute over SONET/SDH interfaces) Specify
the time duration after which the router sets an alarm when it records
a defect at the path layer.
(MPLS fast reroute over SONET/SDH interfaces) Specify
the time duration after which the router sets an alarm when it records
a defect at the line or section layer.
Use to configure the transmit clock source for the interface.
For production networks, configure all STMx ports on the
line module for internal chassis timing. You must also ensure that
the chassis reference clock is of good quality — Stratum 3 or
better, recovered either from a known good STM port or from one of
the BITS inputs.
Although the CLI enables you to specify the keywords internal module to use the line module’s internal
clock, in a production network we recommend that you do not do this.
Instead, specify the keywords internalchassis to use the router’s internal clock.
For production networks, never specify the keyword line to use the line’s receive clock as the transmit
clock. Although the CLI enables this configuration, it is not supported
because jitter transfer is not compliant for this timing and because
pointer adjustments takes place on the outgoing link.
In a nonproduction network, you can configure some ports
with internal clock sources and others with line clock sources. However,
all ports with internal clock sources must use either the router’s
clock or the module’s clock. You cannot configure some ports
on the I/O module to use the router’s clock and others to use
the module’s clock.
To change the clock source of the ports on a cOC3/STM1
I/O module from the router’s clock to the module’s clock
or vice versa, first change the clock source of all ports to the line
setting, and then to the new internal clock setting.
Use to configure paths over channelized SONET and SDH
interfaces.
Specify the correct identifier for the type of interface.
See Interface Types and Specifiers in JUNOSe Command Reference Guide for details of the syntax.
Use to overwrite the automatic setting for the path signal
label (C2) byte.
By default, the value of the C2 byte for the path is determined
by the layers configured above the SONET/SDH interface and set automatically.
The E-series router sets this default value in accordance with RFC
2558. (See References.)
Caution:
Use this command only if you know that the automatic
setting does not match the setting on the remote device. Otherwise,
the remote device might send an unexpected value, and the router might
lose data.
Example
host1(config-controll)#path 2 overhead c2
20
Use the no version to restore
the default setting, in which the value of the C2 byte is determined
by the layers configured above the SONET/SDH interface.
Use to configure the router to use remote defect indications
(RDIs) at the path layer to determine the operational status of a
path.
Example
host1(config-controll)#path 2 trigger alarm
prdi
Use the no version to restore
the default setting, in which the software uses loss of pointer and
AIS defects at the path layer to determine the operational status
of a path.
You can configure T1 and E1 interfaces on paths
and tributaries. To do so, complete the following steps:
Configure the clock source. You must coordinate this setting
with the other end of the line to establish which end is the transmit
(internal) clock and which is the receive (line) clock.
(Optional) Configure the framing format.
(Optional) Enable processing of SNMP link status information
about an interface and its associated tributary.
Configure the T1 or E1 line parameters.
(Optional) Enable processing of SNMP link status information
about a channel group.
(Optional—T1 only) Configure FDL messages.
(Optional) Assign a text description or an alias to the
interface.
path ds1|e1 channel-group description
Use to assign a text description or an alias to a DS1
(T1) or an E1 channel group for channelized SONET and SDH interfaces.
You can use this command to help you identify the interface
and keep track of interface connections.
The description or alias can be a maximum of 80 characters.
Use to configure the transmit clock source for the T1
or E1 interface.
Select a clock as follows:
Specify the keyword line to
use a transmit clock recovered from the line’s receive data
stream.
Specify the keywords internal module to use the line module’s internal clock.
Specify the keywords internalchassis to use the router’s clock.
You can usually accept the default option, line, to use a transmit clock recovered from the line’s
receive data stream, except in rare cases such as back-to-back router
tests. When performing back-to-back router tests, configure one end
of the line as internal and the other end
as line.
On a cOC3/STM1 I/O module, you can configure some interfaces
with internal clock sources and others with line clock sources. However,
all interfaces with internal clock sources must use either the router’s
clock or the module’s clock. You cannot configure some interfaces
on the I/O module to use the router’s clock and others to use
the module’s clock.
To change the clock source of the interfaces on a cOC3/STM1
I/O module from the router’s clock to the module’s clock
or vice versa, first change the clock source of all ports to the line
setting, and then to the new internal clock setting.
Example
host1(config-controll)#path 12 e1 1/4/1 clock
source line
Use the no version to restore
the default value, line.
Use to configure the framing format for a T1 or an E1
interface.
For T1, specify esf (extended
superframe) or sf (superframe). The default
is esf.
The HDLC idle character differs from non–E-series
implementations. For T1 interfaces, if you configure SF, the router
sets the HDLC idle character to 0xFF. If you configure ESF, the router
sets the HDLC idle character to 0x7E.
For E1, specify crc4 or no-crc4. The default is crc4.
Choose a framing format that is compatible with the framing
format at the other end of the line.
Use to configure an FDL message as defined in the ANSI
T1.403 specification.
Note:
The router sends these FDL messages only if you have issued
the path ds1 fdl command with the ansi or all keyword and then issued the path ds1 fdl transmit command.
Use to configure the router to send the specified type
of FDL message on the T1 channel.
By default, the router sends no FDL messages.
Note:
The router sends FDL messages specified with the path ds1 fdl string command
only if you have issued the path ds1 fdl command with the ansi or all keyword. If you specified the att keyword with the path ds1 fdl command, the router sends
only performance data.
Specify the keyword path-id to transmit path identifications every second.
Specify the keyword idle-signal to send idle signals every second.
Specify the keyword test-signal to transmit test signals every second.
Complete the following steps to configure T3 line
parameters. Configure these parameters for both clear channel and
multiplexed T3 lines.
Configure the clock source. You must coordinate this setting
with the other end of the line to establish which end is the transmit
(internal) clock and which is the receive (line) clock.
(Optional) Assign a text description or an alias to the
interface.
(Optional) Configure the framing format.
(Optional) Enable processing of SNMP link status information
about an interface.
(Optional) Configure MDL settings.
(Optional) Configure T1 channels.
path ds3 clock source
Use to configure the transmit clock source for the T3
line.
Select a clock as follows:
Specify the keyword line to
use a transmit clock recovered from the line’s receive data
stream.
Specify the keywords internal module to use the line module’s internal clock.
Specify the keywords internalchassis to use the router’s clock.
You can usually accept the default option, line, to use a transmit clock recovered from the line’s
receive data stream, except in rare cases such as back-to-back router
tests. When performing back-to-back router tests, configure one end
of the line as internal and the other end
as line.
On a cOC3/STM1 I/O module, you can configure some interfaces
with internal clock sources and others with line clock sources. However,
all interfaces with internal clock sources must use either the router’s
clock or the module’s clock. You cannot configure some interfaces
on the I/O module to use the router’s clock and others to use
the module’s clock.
To change the clock source of the interfaces on a cOC3/STM1
I/O module from the router’s clock to the module’s clock
or vice versa, first change the clock source of all ports to the line
setting, and then to the new internal clock setting.
Example
host1(config-controll)#path 12 ds3 1 clock
source line
Use the no version to restore
the default value, line.
You can configure a T3 interface to send MDL messages. MDL messages
are supported only when the T3 framing is set for C-bit parity, the
default setting.
To configure a T3 interface to send MDL messages:
Specify a SONET interface.
host1(config)#controller sonet 8/0
(Optional) Configure the interface to operate in an MDL
carrier environment.
To configure T1 and fractional T1 channels over
T3 interfaces:
Configure the T1 path.
Configure the clock source.
You must coordinate this setting with the other
end of the line to establish which end is the transmit (internal)
clock and which is the receive (line) clock.
(Optional) Assign a text description or an alias to the
interface.
(Optional) Configure the framing format.
(Optional) Enable processing of SNMP link status information
about an interface.
Configure the T1 line parameters.
You can specify parameters for a single channel,
multiple individual channels, ranges of channels, or any combination
of the three types of specifications. For example:
host1(config-controll)#path 12 ds3 1 t1 25-28
(Optional) Enable processing of SNMP link status information
about a channel group.
path ds3 t1
Use to create and configure the T1 path over SONET and
SDH interfaces.
Use to configure the transmit clock source for the T3
line.
Use a transmit clock recovered from the line’s receive
data stream, except in rare cases such as back-to-back router tests.
When performing back-to-back router tests, configure one end of the
line as internal and the other end as line.
Specify the keyword line to
use a transmit clock recovered from the line’s receive data
stream.
Specify the keywords internal module to use the line module’s internal clock.
Specify the keywords internalchassis to use the router’s clock.
On a cOC3/STM1 I/O module, you can configure some ports
with internal clock sources and others with line clock sources. However,
all ports with internal clock sources must use either the router’s
clock or the module’s clock. You cannot configure some ports
on the I/O module to use the router’s clock and others to use
the module’s clock.
To change the clock source of the ports on a cOC3/STM1
I/O module from the router’s clock to the module’s clock
or vice versa, change the clock source of all ports first to the line
setting, and then to the new internal clock setting.
Use to configure an FDL message as defined in the ANSI
T1.403 specification.
Note:
The router sends these FDL messages only if you have issued
the path ds3 t1 fdl command with the ansi or all keyword and then issued the path ds3 t1 fdl transmit command.
Use to configure the router to send the specified type
of FDL message.
By default, the router sends only FDL performance data
messages.
Note:
The router sends FDL messages specified with the path ds3 t1 fdl string command only if you have issued the path ds3 t1 fdl command with the ansi or all keyword. If
you specified the att keyword with the path ds3 t1 fdl command,
the router sends only performance data.
Specify the keyword path-id to transmit path identifications every second.
Specify the keyword idle-signal to send idle signals every second.
Specify the keyword test-signal to transmit test signals every second.
You must configure HDLC over the T3, T1, unframed
E1, or fractional T1/E1 line that you configure on an interface. As Figure 8 shows, HDLC must be the top layer of the
interface stack.
To configure an HDLC channel, specify a serial
interface. For example:
host1(config)#interface serial 4/0:1/1/1/1
Optional Tasks
The following configuration tasks are optional
when you configure an HDLC channel on a channelized T3 interface:
Configure the CRC.
Configure the HDLC idle character.
Enable data inversion on the interface.
Set the MRU.
Set the MTU.
Assign a text description or an alias to the serial interface.
crc
Use to configure the size of the CRC.
Specify the number of bits (16 or 32) that are used to
calculate the frame check sequence (FCS). Both the sender and receiver
must use the same setting.
The CRC is an error-checking technique that uses a calculated
numeric value to detect errors in transmitted data.
A 32-bit CRC should be used to protect longer streams
at faster rates and, therefore, provide better ongoing error detection.
Coordinate this value with the network administrator on
the other end of the line.
If you set this value with a different value for another
protocol, such as IP, the router uses the lower value. The lower MRU
might cause unexpected results in the network.
Example
host1(config-if)#mru 1500
Use the no version to restore
the default, 1600 bytes.
You should coordinate this value with the network administrator
on the other end of the line.
You can set a different MTU value in higher-level protocols,
such as IP. If you do, the router uses the lower value. The lower
MTU might cause unexpected results in the network.
Example
host1(config-if)#mtu 1500
Use the no version to restore
the default, 1600 bytes.
