Configuration procedure
The AM interface supports all commands available on the asynchronous interface and the modem,
except for the modem auto-answer and baudrate commands. For more information about modem
configuration, see Layer 2—WAN Configuration Guide.
In addition, to set the baud rate for an AM interface, you must use the speed command in user line view.
For more information, see Fundamentals Configuration Guide.
This section only describes the interface properties configuration. Depending on the network
requirements, you might also need to configure PPP, DDR, IP address, firewall, and interface backup.
To configure an AM interface:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enter AM interface view.
interface analogmodem
interface-number
N/A
3. Set the coding format of the
modem.
country-code area-name
The default is united-states.
For more information about this
command, see Layer 2—WAN
Command Reference.
4. (Optional.) Set the interface
description.
description text
By default, the description of an
AM interface is interface name
Interface, for example,
Analogmodem2/4/0 Interface.
5. Set the operating mode.
async-mode { flow | protocol }
By default, an AM interface
operates in flow mode.
When an AM interface is
operating in flow mode, no data
link layer protocol is available.
When operating in protocol mode,
the AM interface uses PPP as the
data link layer protocol.
6. (Optional.) Enable local
loopback.
loopback
By default, local loopback is
disabled.
7. Set the MTU.
mtu size The default is 1500 bytes.
8. Set the keepalive transmission
interval.
timer-hold seconds The default is 10 seconds.
9. (Optional.) Eliminate the
pulses with a width less than
3.472 μs.
eliminate-pulse
By default, the pulses with a width
less than 1.472 μs are eliminated.
10. Set the MRU for an AM
interface operating in flow
mode.
phy-mru mrusize The default MRU is 1700 bytes.
11. (Optional.) Set the intended
bandwidth for the AM
interface.
bandwidth bandwidth-value
By default, the expected
bandwidth (in kbps) is the interface
baud rate divided by 1000.
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