Specifications

Configuring and Managing Integrated Modems
Managing Modems
DC-65
Cisco IOS Dial Technologies Configuration Guide
V.120 Bit Rate Adaptation Standard
ITU-T Recommendation V.120 revised by the ITU-T Study Group 14. V.120 describes a standard that can
be used for adapting terminals with non-ISDN standard network interfaces to an ISDN. It is intended to
be used between two terminal adapter (TA) functional groups, between two ISDN terminal (TE1)
functional groups, between a TA and a TE1, or between either a TA or TE1 and an interworking facility
inside a public or private ISDN.
V.120 allows for reliable transport of synchronous, asynchronous, or bit transparent data over ISDN
bearer channels. Cisco provides three V.120 support features for terminal adapters that do not send the
low-layer compatibility fields or bearer capability V.120 information:
• Answer all incoming calls as V.120—Static configuration used when all remote users have
asynchronous terminals and need to connect with a vty on the router.
• Automatically detect V.120 encapsulation—Encapsulation dynamically detected and set.
• Enable V.120 support for asynchronous access over ISDN.
For terminal adapters that send the low-layer compatibility or bearer capability V.120 information,
mixed V.120 and ISDN calls are supported. No special configuration is required.
V.120 is a digital rate adaptation and cannot be done on NM-AM network module analog modems.
MICA DSP firmware does not have the code to terminate V.120 calls.
NextPort supports only a subset of V.120 functionalities that are supported by Cisco IOS software.
Therefore, certain V.120 calls still will need to be terminated on the CPU, even if the chassis has
available NextPort modems.
Managing Modems
To manage modems, perform the tasks in the following sections; the tasks you need to perform depend
upon the type and needs of your system:
• Managing SPE Firmware
• Configuring Modems in Cisco Access Servers
• Configuring Cisco Integrated Modems Using Modem Attention Commands
• Configuring Modem Pooling
• Configuring Physical Partitioning
• Configuring Virtual Partitioning
• Configuring Call Tracker
• Configuring Polling of Link Statistics on MICA Modems
• Configuring MICA In-Band Framing Mode Control Messages
• Enabling Modem Polling
• Setting Modem Poll Intervals
• Setting Modem Poll Retry
• Collecting Modem Statistics
• Troubleshooting Using a Back-to-Back Modem Test Procedure
• Clearing a Direct Connect Session on a Microcom Modem