R2511-HP MSR Router Series Interface Command Reference(V5)

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Default
Loopback is disabled.
Views
CT1/PRI interface view
Default command level
2: System level
Parameters
local: Enables the CT1/PRI interface to perform local loopback.
payload: Enables the interface to perform external payload loopback.
remote: Enables the interface to perform remote loopback.
Usage guidelines
Loopback is mainly used to check the condition of interfaces or cables. Disable loopback in other cases.
You can bundle timeslots on a CT1/PRI interface to form a serial interface and encapsulate it with PPP.
After you enable loopback on this serial interface, it is normal that the state of the link layer protocol is
reported down.
Examples
# Enabled remote loopback on interface T1 2/0.
<Sysname> system-view
[Sysname] controller t1 2/0
[Sysname-T1 2/0] loopback remote
looptest (CT1/PRI interface)
Use looptest to perform a loop test on a synchronous serial interface created for T1 or T1-F.
Syntax
looptest [ -c count | -p { pattern | special { ascending | descending | random } } | -s packetsize | -t
timeout ] * interface type number
Views
Any view
Parameters
-c count: Sets the number of test packets, in the range of 1 to 1 to 4294967295. The default number is
5.
-p pattern: Sets the padding content for test packets, which is a hexadecimal number in the range of 0
to FFFFFFFF. For example, -p ff pads FF to all test packets. By default, 0x55 and 0xAA are padded
alternately.
ascending: Pads test packets with a hexadecimal number from 0x00 to 0xff in turn.
descending: Pads test packets with a hexadecimal number from 0xff to 0x00 in turn.
random: Pads test packets with a hexadecimal number from 0xff to 0x00 at random.
-s packetsize: Sets the size of test packets (excluding the 12-byte packet header), in the range of 0 to
1688 bytes. The default size is 52 bytes.