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Cisco AS5800 Operations, Administration, Maintenance, and Provisioning Guide
DOC-7810814=
Chapter 3 Operations
Verifying Modem Performance
Table 3-2 describes some of the significant fields shown in the previous example:
Understanding Modem Modulation Standards
To optimize modem connect speeds, you must understand the basic modem modulation standards.
This section provides the basic rules for achieving maximum V.34 and V.90 modulation speeds:
• V.34 Basic Rules, page 3-7
• V.90 Basic Rules, page 3-8
V.34 Basic Rules
V.34 modulation should work on any land-line voiceband circuit. V.34 supports speeds ranging from
2400 to 33600 bps.
Speed is a function of:
• The amount of usable spectrum across the channel (for example, 2400 to 3429 Hz)
• The signal to noise ratio (SNR)
Table 3-2 Show TTY Line Field Descriptions
Field Description
Capabilities
Describes different aspects of the line:
• The flowcontrol hardware command displays as “Hardware Flowcontrol In, Hardware
Flowcontrol Out.”
• The modem inout command displays as “modem callout.”
• The text “Line usable as async interface” means there is an “interface async N” that
corresponds to “line N.”
• The text “Modem RI is CD” displays for historical reasons.
Modem state
Displays the current status of the modem.
Possible values include:
• Idle—Modem is ready for incoming and outgoing calls.
• Conn—Modem is connected to a remote host.
• Busy—Modem is out of service and not available for calls.
• D/L—Modem is downloading firmware.
• Bad—Modem is in an inoperable state, which is manually configured by the modem bad
command.
• Bad*—During initial power-up testing, the modem startup-test command automatically put
the modem in an inoperable state.
• Reset—Modem is in reset mode.
• Bad FW—The downloaded modem firmware is not usable.
Modem Hardware state
Displays the EIA/TIA-232 signal state status.
CTS and no DSR are incoming signals. DTR and RTS are outgoing signals. NoDSR means that no
call is currently connected.
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