DNIS and Modem Pooling Using a CAS T1 LinePrintable Pdf
Document ID: 9566
Introduction Prerequisites
Requirements
Components Used
Conventions. Basics of Modem Pooling and CAS Configuration
Network Diagram
Configurations Verify
Debugs and Analyses: Sample Configuration with Two Modem Pools
Debug Analysis: Sample Configuration with One Modem Pool NetPro Discussion Forums - Featured Conversations Related Information
Introduction
This document describes how to configure Digital Number Identification Service (DNIS) support for a
channelized T1 line to enable modem pooling. Two sample configurations are included:
Multiple modem pools
One modem pool with one modem
Prerequisites
Requirements
Before you attempt this configuration, ensure that you meet these requirements:
Cisco IOS® Software Release 11.2(10)P or 11.3(1.1)T or later
Channelized T1 that supports the e&m wink-start signaling (e&m-fgb) command
Modem ISDN channel aggregation (MICA) modems with portware 2.0.1.7 or later
Note: Channel associated signaling (CAS)-DNIS is not supported for Microcom.
If you use Remote Dial-In User Service (RADIUS) as your authentication protocol, you need to know
RADIUS (IETF) Accounting Attribute 30 (Station-ID).
Station-ID allows the Network Access Server (NAS) to send the number the user called as part of the
Access-Request packet (with DNIS or similar technology). Station-ID is supported only on ISDN and
modem calls on the Cisco AS5x00 when used with Primary Rate Interface (PRI).
Components Used
This document is not restricted to specific software and hardware versions.
The information in this document was created from the devices in a specific lab environment. All of the
devices used in this document started with a cleared (default) configuration. If your network is live, make sure
that you understand the potential impact of any command.
Conventions
Refer to Cisco Technical Tips Conventions for more information on document conventions.
Basics of Modem Pooling and CAS Configuration
In order to configure E&M Feature Group-B (FGB) signaling to support modem pooling and DNIS over
channelized T1 lines, you must specify the multifrequency (MF) or dual tone multifrequency (DTMF) tone
type.
If you configure DNIS as part of the cas-group command, the system collects DNIS digits for incoming
calls. These digits are redirected to specific modem pools. You must use MICA modems and have at least ten
percent of them in the default modem pool. Free modems are needed in the default pool to detect the incoming
called number or DNIS before the call is directed to the appropriate modem pool. Therefore, a second modem
is needed to handle each incoming call.
Note: Make sure your switch provides inband address information for incoming analog calls before you
enable this feature.
Tip: When the current called number is shorter than the previous called number, the Cisco access server
receives incorrect DNIS for CAS/R2. This incorrect information can affect modem pooling and can occur as
users call from within the local area, from another state, or from another country. If the number is not an 800
number, it is possible that the length of the dialed number is not constant. The access server remembers the
longest dialed number on that modem.
Because Loop Start and Ground Start trunks require DTMF signaling, they do not receive DNIS or automatic
number identification (ANI) address information sent by the telephone company central office on dial-in
calls. In order to correct this, additional parameters must be set for the modem.
Network Diagram
This document uses this network setup:
Configurations
Sample Configuration with Two Modem Pools
This configuration includes two configured modem pools: PPP has 24 modems allocated and DEC has 20
modems allocated. The remaining four modems are automatically assigned to the default modem pool. The
modems in the default modem pool answer the initial call and then direct the call to the proper modem-pool
for modem allocation.
Four modems in the default pool can cause a problem. The problem is that when five or more users attempt to
dial in simultaneously, only four can connect and the remaining user hears a busy signal. These are a few
workarounds:
If you use a PRI instead of CAS, DNIS information is decoded by the Cisco IOS.
When you use a CAS service, buy more modems than needed. The number of additional modems
depend on the model of the Cisco access server.
When you use a CAS service, allocate enough modems to the default pool so that most users can
connect most of the time.
Configuration with One Modem Pool
In this example, only one modem pool is configured with one modem:
modem-pool part1
pool-range 1
called-number 4085551345 max-conn 1
!
controller T1 0
framing esf
clock source line primary
cas-group 0 timeslots 1-24 type e&m-fgb dtmf dnis
Verify
This section provides information you can use to confirm your configuration is working properly.
Certain show commands are supported by the Output Interpreter Tool ( registered customers only) , which allows
you to view an analysis of show command output.
Debugs and Analyses: Sample Configuration with Two Modem Pools
Debug analyses are included for a PPP and for EXEC sessions.
eval#show version
Cisco Internetwork Operating System Software
IOS (tm) 5300 Software (C5300-JS-M), Version 11.2(11)P1, RELEASE SOFTWARE
(fc1)
Copyright (c) 1986-1998 by cisco Systems, Inc.
Compiled Wed 21-Jan-98 00:22 by dschwart
Image text-base: 0x600088F0, data-base: 0x607A6000
ROM: System Bootstrap, Version 11.2(9)XA, RELEASE SOFTWARE (fc2)
BOOTFLASH: 5300 Software (C5300-BOOT-M), Version 11.2(9)XA1, RELEASE SOFTWARE (fc1)
eval uptime is 3 hours, 42 minutes
System restarted by reload
System image file is "flash:c5300-js-mz.112-11.P1", booted via flash
cisco AS5300 (R4K) processor (revision A.22) with 65536K/16384K bytes of memory.
SuperLAT software copyright 1990 by Meridian Technology Corp).
X.25 software, Version 2.0, NET2, BFE and GOSIP compliant.
TN3270 Emulation software.
Primary Rate ISDN software, Version 1.0.
Backplane revision 2
Manufacture Cookie Info:
EEPROM Type 0x0001, EEPROM Version 0x01, Board ID 0x30,
Board Hardware Version 1.16, Item Number 73-2414-3,
Board Revision C0, Serial Number 07801222,
PLD/ISP Version 255.255, Manufacture Date 17-Mar-1998.
1 Ethernet/IEEE 802.3 interface(s)
1 FastEthernet/IEEE 802.3 interface(s)
48 terminal line(s)
4 Channelized T1/PRI port(s)
128K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read/Write)
4096K bytes of processor board Boot flash (Read/Write)
Configuration register is 0x2142
show modem-pool Before Modem Dialin
eval#
eval#show modem-pool
modem-pool: System-def-Mpool
modems in pool: 4 active conn: 0
20 no free modems in pool
modems in pool: 24 active conn: 0
0 no free modems in pool
called_party_number: 5551345
max conn allowed: 24, active conn: 0
0 max-conn exceeded, 0 no free modems in pool
modem-pool: DEC
modems in pool: 20 active conn: 0
0 no free modems in pool
called_party_number: 5551370
0 max-conn exceeded, 0 no free modems in pool
eval#
Win95 PPP Dialin to Modem-Pool PPP
eval#show debug
General OS:
Modem control/process activation debugging is on
PPP:
PPP protocol negotiation debugging is on
Modem Management:
Modem Management Call Switching Module debugging is on
eval#
eval#
*Oct 17 09:51:26.099: VDEV_ALLOCATE: slot 1 and port 46 is allocated.
*Oct 17 09:51:26.099: CSM_RX_CAS_EVENT_FROM_NEAT:(0062):
EVENT_CALL_DIAL_IN at slot 1 and port 46
*Oct 17 09:51:26.099: CSM_PROC_IDLE: CSM_EVENT_DSX0_CALL at slot 1, port 46
*Oct 17 09:51:26.099: Mica Modem(1/46): Configure(0x0)
*Oct 17 09:51:26.099: Mica Modem(1/46): Configure(0x2)
*Oct 17 09:51:26.099: Mica Modem(1/46): Call Setup
*Oct 17 09:51:26.239: Mica Modem(1/46): State Transition to Call Setup
*Oct 17 09:51:26.239: Mica Modem(1/46): Went offhook
*Oct 17 09:51:30.771: CSM_PROC_IC2_COLLECT_ADDR_INFO:
CSM_EVENT_ADDR_INFO_COLLECTED (dnis = 5551345) at slot 1, port 46
*Oct 17 09:51:30.771: VDEV_ALLOCATE: slot 1 and port 2 is allocated.
*Oct 17 09:51:30.771: Mica Modem(1/2): Configure(0x0)
*Oct 17 09:51:30.771: Mica Modem(1/2): Configure(0x2)
*Oct 17 09:51:30.771: Mica Modem(1/2): Call Setup
*Oct 17 09:51:30.771: Mica Modem(1/46): Soft Reset
*Oct 17 09:51:30.855: Mica Modem(1/46): State Transition to Terminating
*Oct 17 09:51:30.911: Mica Modem(1/2): State Transition to Call Setup
*Oct 17 09:51:30.911: Mica Modem(1/2): Went offhook
*Oct 17 09:51:30.911: CSM_IC3_WAIT_FOR_SWITCH_OVER:
CSM_EVENT_MODEM_OFFHOOK at slot 1, port 2*Oct 17 09:51:30.915: Mica Modem(1/46): State Transition to Idle
*Oct 17 09:51:30.915: Mica Modem(1/46): Went onhook
*Oct 17 09:51:30.915: CSM_PROC_IC6_OC8_DISCONNECTING:
CSM_EVENT_MODEM_ONHOOK at slot 1, port 46
*Oct 17 09:51:30.915: VDEV_DEALLOCATE: slot 1 and port 46 is deallocated
*Oct 17 09:51:31.803: CSM_RX_CAS_EVENT_FROM_NEAT:(0062):
EVENT_CHANNEL_CONNECTED at slot 1 and port 2
*Oct 17 09:51:31.803: CSM_PROC_IC4_WAIT_FOR_CARRIER:
CSM_EVENT_DSX0_CONNECTED at slot 1, port 2
*Oct 17 09:51:31.803: Mica Modem(1/2): Link Initiate
*Oct 17 09:51:31.927: Mica Modem(1/2): State Transition to Connect
*Oct 17 09:51:36.955: Mica Modem(1/2): State Transition to Link
*Oct 17 09:51:49.171: Mica Modem(1/2): State Transition to Trainup
*Oct 17 09:51:52.467: Mica Modem(1/2): State Transition to EC Negotiating
*Oct 17 09:51:53.007: Mica Modem(1/2): State Transition to Steady State
*Oct 17 09:51:53.999: TTY3: DSR came up
*Oct 17 09:51:53.999: tty3: Modem: IDLE->READY
%LINK-3-UPDOWN: Interface Async3, changed state to up
show modem-pool After Connect (Modem-Pool PPP)
eval#show modem-pool
modem-pool: System-def-Mpool
modems in pool: 4 active conn: 0
20 no free modems in pool
modem-pool: ppp
modems in pool: 24 active conn: 1
0 no free modems in pool
called_party_number: 6561345
max conn allowed: 24, active conn: 1
0 max-conn exceeded, 0 no free modems in pool
modem-pool: DEC
modems in pool: 20 active conn: 0
0 no free modems in pool
called_party_number: 6561370
max conn allowed: 20, active conn: 0
0 max-conn exceeded, 0 no free modems in pool
CSM_EVENT_ADDR_INFO_COLLECTED (dnis = 5551370) at slot 1, port 47
*Oct 17 09:52:36.939: VDEV_ALLOCATE: slot 1 and port 31 is allocated.
*Oct 17 09:52:36.939: Mica Modem(1/31): Configure(0x0)
*Oct 17 09:52:36.939: Mica Modem(1/31): Configure(0x2)
*Oct 17 09:52:36.939: Mica Modem(1/31): Call Setup
*Oct 17 09:52:36.939: Mica Modem(1/47): Soft Reset
*Oct 17 09:52:37.019: Mica Modem(1/47): State Transition to Terminating
*Oct 17 09:52:37.075: Mica Modem(1/31): State Transition to Call Setup
*Oct 17 09:52:37.075: Mica Modem(1/31): Went offhook
*Oct 17 09:52:37.075: CSM_IC3_WAIT_FOR_SWITCH_OVER:
CSM_EVENT_MODEM_OFFHOOK at slot 1, port 31
*Oct 17 09:52:37.079: Mica Modem(1/47): State Transition to Idle
*Oct 17 09:52:37.079: Mica Modem(1/47): Went onhook
*Oct 17 09:52:37.079: CSM_PROC_IC6_OC8_DISCONNECTING
:
CSM_EVENT_MODEM_ONHOOK at slot 1, port 47
*Oct 17 09:52:37.079: VDEV_DEALLOCATE: slot 1 and port 47 is deallocated
*Oct 17 09:52:37.967: CSM_RX_CAS_EVENT_FROM_NEAT:(0063):
EVENT_CHANNEL_CONNECTED at slot 1 and port 31
*Oct 17 09:52:37.967: CSM_PROC_IC4_WAIT_FOR_CARRIER:
CSM_EVENT_DSX0_CONNECTED at slot 1, port 31
*Oct 17 09:52:37.967: Mica Modem(1/31): Link Initiate
*Oct 17 09:52:38.095: Mica Modem(1/31): State Transition to Connect
*Oct 17 09:52:42.467: Mica Modem(1/31): State Transition to Link
*Oct 17 09:52:51.447: Mica Modem(1/31): State Transition to Trainup
*Oct 17 09:52:53.603: Mica Modem(1/31): State Transition to EC Negotiating
*Oct 17 09:52:54.679: Mica Modem(1/31): State Transition to Steady State
*Oct 17 09:52:55.079: TTY32: DSR came up
*Oct 17 09:52:55.079: tty32: Modem: IDLE->READY
*Oct 17 09:52:55.079: TTY32: EXEC creation
eval#
show modem-pool After Exec Dialin
eval#show modem-pool
modem-pool: System-def-Mpool
modems in pool: 4 active conn: 0
20 no free modems in pool
modem-pool: ppp
modems in pool: 24 active conn: 1
0 no free modems in pool
called_party_number: 6561345
max conn allowed: 24, active conn: 1
0 max-conn exceeded, 0 no free modems in pool
modem-pool: DEC
modems in pool: 20 active conn: 1
0 no free modems in pool
called_party_number: 6561370
max conn allowed: 20, active conn: 1
0 max-conn exceeded, 0 no free modems in pool
Debug Analysis: Sample Configuration with One Modem Pool
As you see in the debugs, the first connection is to modem 1/7. Then the router gets the DNIS info and routes
the call to specifed modem 1/0 as configured.
Apr 2 20:58:05.588: VDEV_ALLOCATE: slot 1 and port 7 is allocated.
Apr 2 20:58:05.588: CSM_RX_CAS_EVENT_FROM_NEAT:(0007):
EVENT_CALL_DIAL_IN at slot 1 and port 7
Apr 2 20:58:05.588: CSM_PROC_IDLE: CSM_EVENT_DSX0_CALL at slot 1, port 7
Apr 2 20:58:05.588: Mica Modem(1/7): Configure(0x0)
Apr 2 20:58:05.588: Mica Modem(1/7): Configure(0x2)
Apr 2 20:58:05.588: Mica Modem(1/7): Call Setup
Apr 2 20:58:05.740: Mica Modem(1/7): State Transition to Call Setup
Apr 2 20:58:05.740: Mica Modem(1/7): Went offhook
Apr 2 20:58:05.744: CSM_PROC_IC1_RING: CSM_EVENT_MODEM_OFFHOOK at slot 1, port
Apr 2 20:58:09.744: CSM_PROC_IC2_COLLECT_ADDR_INFO: CSM_EVENT_ADDR_INFO_COLLECTED
(dnis = ) at slot 1, port 7
Apr 2 20:58:09.744: VDEV_ALLOCATE: slot 1 and port 0 is allocated.
Apr 2 20:58:09.744: Mica Modem(1/0): Configure(0x0)
Apr 2 20:58:09.744: Mica Modem(1/0): Configure(0x2)
Apr 2 20:58:09.744: Mica Modem(1/0): Call Setup
Apr 2 20:58:09.744: Mica Modem(1/7): Soft Reset
Apr 2 20:58:09.812: Mica Modem(1/7): State Transition to Terminating
Apr 2 20:58:09.872: Mica Modem(1/0): State Transition to Call Setup
Apr 2 20:58:09.872: Mica Modem(1/0): Went offhook
Apr 2 20:58:09.872: CSM_IC3_WAIT_FOR_SWITCH_OVER:
CSM_EVENT_MODEM_OFFHOOK at slot 1, port 0
Apr 2 20:58:09.872: Mica Modem(1/7): State Transition to Idle
Apr 2 20:58:09.872: Mica Modem(1/7): Went onhook
Apr 2 20:58:09.872: CSM_PROC_IC6_OC8_DISCONNECTING:
CSM_EVENT_MODEM_ONHOOK at slot 1, port 7
Apr 2 20:58:09.872: VDEV_DEALLOCATE: slot 1 and port 7 is deallocated
Apr 2 20:58:09.988: CSM_RX_CAS_EVENT_FROM_NEAT:(0007):
EVENT_CHANNEL_CONNECTED at slot 1 and port 0
Apr 2 20:58:09.988: CSM_PROC_IC4_WAIT_FOR_CARRIER:
CSM_EVENT_DSX0_CONNECTED at slot 1, port 0
Apr 2 20:58:09.988: Mica Modem(1/0): Link Initiate
Apr 2 20:58:10.112: Mica Modem(1/0): State Transition to Connect
Apr 2 20:58:14.488: Mica Modem(1/0): State Transition to Link
Apr 2 20:58:23.116: Mica Modem(1/0): State Transition to Trainup
Apr 2 20:58:25.272: Mica Modem(1/0): State Transition to EC Negotiating
Apr 2 20:58:26.228: Mica Modem(1/0): State Transition to Steady State
Apr 2 20:58:33.480: Mica Modem(1/6): State Transition to Terminating
Apr 2 20:58:35.152: %LINK-5-CHANGED: Interface Async7, changed state to reset
Apr 2 20:58:35.216: Mica Modem(1/6): State Transition to Idle
Apr 2 20:58:35.216: Mica Modem(1/6): Went onhook
Apr 2 20:58:35.216: CSM_PROC_IC5_OC6_CONNECTED:
CSM_EVENT_MODEM_ONHOOK at slot 1, port 6
Apr 2 20:58:35.216: VDEV_DEALLOCATE: slot 1 and port 6 is deallocated
Apr 2 20:58:35.240: %DSX0-5-RBSLINEDBUSYOUT:
RBS of controller 0 timeslot 5 is dynamic busyout
Apr 2 20:58:36.124: %LINEPROTO-5-UPDOWN:
Line protocol on Interface Async7, changed state to down
Apr 2 20:58:36.896: Mica Modem(1/0):
State Transition to Steady State Speedshifting
Apr 2 20:58:37.372: Mica Modem(1/0):
State Transition to Steady State
Apr 2 20:58:38.488: %DSX0-5-RBSLINEUNBUSYOUT:
RBS of controller 0 timeslot 5 is unbusyout
Apr 2 20:58:41.128: %LINK-3-UPDOWN:
Interface Async7, changed state to down
Debug When Another Number is Called
Apr 2 21:00:05.234: Mica Modem(1/0): State Transition to Terminating
Apr 2 21:00:05.650: Mica Modem(1/0): State Transition to Idle
Apr 2 21:00:05.650: Mica Modem(1/0): Went onhook
Apr 2 21:00:05.650: CSM_PROC_IC5_OC6_CONNECTED:
CSM_EVENT_MODEM_ONHOOK at slot 1, port 0
Apr 2 21:00:05.650: VDEV_DEALLOCATE: slot 1 and port 0 is deallocated
Apr 2 21:00:08.026: %DSX0-5-RBSLINEDBUSYOUT:
RBS of controller 0 timeslot 24 is dynamic busyout
Apr 2 21:00:08.490: %DSX0-5-RBSLINEUNBUSYOUT:
RBS of controller 0 timeslot 24 is unbusyout
Apr 2 21:00:17.010: VDEV_ALLOCATE: slot 1 and port 8 is allocated.
Apr 2 21:00:17.010: CSM_RX_CAS_EVENT_FROM_NEAT:(0008):
EVENT_CALL_DIAL_IN at slot 1 and port 8
Apr 2 21:00:17.010: CSM_PROC_IDLE: CSM_EVENT_DSX0_CALL at slot 1, port 8
Apr 2 21:00:17.010: Mica Modem(1/8): Configure(0x0)
Apr 2 21:00:17.010: Mica Modem(1/8): Configure(0x2)
Apr 2 21:00:17.010: Mica Modem(1/8): Call Setup
Apr 2 21:00:17.154: Mica Modem(1/8): State Transition to Call Setup
Apr 2 21:00:17.154: Mica Modem(1/8): Went offhook
Apr 2 21:00:17.154: CSM_PROC_IC1_RING: CSM_EVENT_MODEM_OFFHOOK at slot 1, port 8
Apr 2 21:00:18.802: CSM_RX_CAS_EVENT_FROM_NEAT:(0008):
EVENT_CHANNEL_CONNECTED at slot 1 and port 8
Apr 2 21:00:18.802: CSM_PROC_IC4_WAIT_FOR_CARRIER:
CSM_EVENT_DSX0_CONNECTED at slot 1, port 8
Apr 2 21:00:18.802: Mica Modem(1/8): Link Initiate
Apr 2 21:00:18.890: Mica Modem(1/8): State Transition to Connect
Apr 2 21:00:23.323: Mica Modem(1/8): State Transition to Link
Apr 2 21:00:32.363: Mica Modem(1/8): State Transition to Trainup
Apr 2 21:00:34.523: Mica Modem(1/8): State Transition to EC Negotiating
Apr 2 21:00:35.543: Mica Modem(1/8): State Transition to Steady State
Apr 2 21:00:46.079: Mica Modem(1/8): State Transition to Steady State Speedshifting
Apr 2 21:00:46.679: Mica Modem(1/8): State Transition to Steady State
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