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

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Related commands
• register-value
• force-metering enable
pcm
Use pcm to configure a companding law used for quantizing signals.
Use undo pcm to restore the default.
Syntax
pcm { a-law | -law }
undo pcm
Default
The companding law for VE1 interfaces is A-law, while that for VT1 interfaces is -law.
Views
Voice subscriber line view
Default command level
2: System level
Parameters
a-law: Companding A-law, used in most part of the world other than North America and Japan, such as
China, Europe, Africa, and South America.
-law: Companding -law, used in North America and Japan.
Usage guidelines
Companding laws are adopted to quantize signals unevenly for the purpose of reducing noise and
improving signal-to-noise ratio. Underpinning this approach are the statistics about voice signals, which
indicate that lower power signals are more likely to be present than higher power signals.
According to CCITT, when devices in two countries use different companding schemes to communicate,
the side using -law is responsible for converting signals to A-law.
Examples
# Adopt -law companding for signal quantization.
<Sysname> system-view
[Sysname] subscirber-line1/0:0
[Sysname-subscriber-line1/0:0] pcm u-law
pri-set
Use pri-set to bundle timeslots on an E1 or T1 interface into a PRI group.
Use undo pri-set to remove the bundle.
Syntax
pri-set [ timeslot-list range ]
undo pri-set