Copyright © 1998 Cisco Systems, Inc. All Rights Reserved.
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Digital Modem Features/Benefits
The Cisco 3600, installed with the digital modem network
modules, offers the most flexible, scalable, manageable,
andhigh-performance dial access solution available in the market
today.
Thesenew network modules utilize either the single or dual
PRInetwork module, the 4 and 8 port BRI Network Modules, or
the mixed media Fast Ethernet/PRI network module to offer
support for up to 90 remote modem users (using two digital
networkmodules), at speeds up to 56 kbps. Each network module
supports up to 30 digital modems. Flexible LAN topologies
includingEthernet, Fast Ethernet, and Token Ring are supported.
Theinternal digital modem network module is available with
6, 12, 18, 24, and 30 modems preinstalled, and can also be
upgraded on site, from say 18 to 24 modems, as simply
asupgrading computer memory! This scenario gives the
maximumflexibility to grow a dial-in solution as the remote user
base grows.
Supportfor the new 56K modem technology allows users to
achievemaximum data transfer rates, while still allowing support
forV.34 technologies. The modems are software upgradable, and
willsupport future standards as they become available. This high
speed ensures the fastest downloads of Web pages and files.
Note: Actualspeeds vary, depending on line conditions. Because
of FCC limitations, speeds in the United States are less than 56
kbps.
The Cisco 3600 can take incoming Integrated Services Digital
Network(ISDN) or voice calls and automatically switch them to
theappropriate internal circuitry. The PRI/BRI switching is based
on Q.931 messaging in the ISDN D channel. This out-of-band
signaling channel provides a way for the telephone network to
label each call as to the type of call. Specifically, when an
incoming call is labeled “voice” by the telephone network, the
Cisco3600 directs it to one of its modems. When a call is labeled
“ISDN data”, it is directed to one of its High-Level Data Link
Control (HDLC) controllers. The benefits here are one phone
number for modem and ISDN users. R2 and CT1 interfaces also
support this switching ability.
The Cisco 3600 provides complete centrally managed
modem capabilities, key requirements for branches and
enterprises building midsized dial-in pools. The Cisco 3600
modems can be managed via the same Simple Network
Management Protocol (SNMP)-based tools used to manage the
rest of the network, providing network managers with one
solution at a central management point. Optional enhanced
modemmanagement (Management Modem Technology License
[MMTL])capabilities allow for the gathering of modem statistics,
real-time call-in-progress, monitoring modem activity log,
modemhard/soft busy out, and the ability to accomplish modem
firmware upgrades.
The installed modems can be utilized by LAN users for
dial-outand fax-out applications, utilizing 3rd party applications
such as the one available from Tactical Software. The modems
can be assigned as dial-in, dial-out, or both. Dial-out support
allows the LAN users to utilize the modems during the day for
outgoing calls, and use the same modems in the evening for
incoming calls from home users.
The ever-expanding numbers of remote users can be easily
accommodated with the support for Multilink Multichassis PPP,
allowing dial-in pools of lines to span numerous Cisco 3600
routers.Through the use of Layer 2 Forwarding (L2F) technology
andCisco’s exclusive Stack Group Bidding Protocol (SGBP), the
Cisco3600 can grow to meet the requirements of the fast-growing
and frequently changing dial environments. Since the essential
building block is a relatively small investment, enterprises and
branch offices can scale from very small to larger installations.
TheCisco IOS®software can help maximize dial bandwidth,
utilizing numerous features such as bandwidth on demand and
protocol spoofing. These software features directly reduce line
usage and reduce the cost associated with a remote access
solution.
Loweroperating costs are achievable with the Cisco 3600’s
set of central management. The Cisco 3600 and its internal
modemscan be managed with CiscoWorks software. In addition,
Cisco’s configuration management capabilities provide network
managers with complete control over network statistics and the
ability to configure and tune network operations from a central
location. Finally, comprehensive debugging tools in Cisco IOS
software substantially reduce the time and cost associated with
problem isolation andcorrection.