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RAS Query

We have a Cisco 3620 router with a 12 port DM, and an E1 / PRI + 1FE adaptor which we use for RAS (incoming only). I believe the portware is bundled with the IOS version (2720) and the IOS version we use is c3620-ik9s-mz.122-3d.bin. Could someone plz tell me why Slot one on the following output shows Slot 1:MICA-6DM Firmware ? Is this because there is 6DMs per MICA ?

#sh modem version

Slot 1:MICA-6DM Firmware, Source - IOS

CP ver 2720 - 5/30/2000, CheckSum 55E02A4A.

SP ver 2720 - 5/30/2000.

MICA 0: HW Version 1.0, Serial Number 19122560.

MICA 1: HW Version 1.0, Serial Number 19122871.

MICA 2: Not Installed.

MICA 3: Not Installed.

MICA 4: Not Installed.

We don't have lots of users dialing in to this router yet, but we are getting some engaged tones, however a redial straight away works. Is this normal behaviour, or should incoming calls be routed to a free modem if there is one ? Our current call success rate is 95%, however, it has been down to 80%

no ip address

dialer rotary-group 1

isdn switch-type primary-net5

isdn incoming-voice modem

isdn T321 0

interface Group-Async1

description ** Mags RAS users to blah **

ip unnumbered FastEthernet0/0

ip access-group 101 in

ip helper-address

ip helper-address

encapsulation ppp

dialer in-band

dialer idle-timeout 600

dialer-group 1

async mode dedicated

peer default ip address dhcp

ppp authentication pap user-radius

group-range 33 44

Any advice would be appreciated.



Re: RAS Query

Slot 1:MICA-6DM Firmware, Source - IOS



Means slot 1 on the chassis has MICA -6DM modules installed on a NM, MICA 0 / 1 means there are 2 x 6DM modules (12 modems) on that network module.

The firmware is that is built-in in IOS (it can also read like Firmware, Source- flash:/ pw2720.... if it was seperately flashed)

If we have free modems available then the call will automatically be routed to the next available modem....when user gets engaged tone ( ensure we have free modems available) , do we see the call hit the 3600? deb isdn q931will indicate that.

Do we have ISDN users also call in? Ensure that the total DS0s have not maxed out in use.

Thanks, Mak.


Re: RAS Query

Thanks for the reply.

I've just been running some tests, and have been getting the engaged when there were no other users dialed in. Also i am not seeing the engaged call hit the router so no debug output.




Re: RAS Query

Engaged tone is generated by the switch based on non availabilty of resources at the router, how ever if the call is not making to the router at all indicates this could be a telco switch problem.

Have the telco (T1 provider) online & generate a few test calls.

Thanks, Mak.


Re: RAS Query


Spoke to the telco, they couldn't see any problems on the E1 cicruit.

They did suggest that calls might not be being disconnected immediately and all DS0s could be busy, but i think "show controllers e1 call-counters" proves otherwise. Any thoughts?

E1 0/0:

DS0's Active: 0

DS0's Active High Water Mark: 3

TimeSlot Type TotalCalls TotalDuration

1 pri 128 1d07h

2 pri 21 05:38:21

3 pri 1 00:09:24

4 pri 0 00:00:00

5 pri 0 00:00:00

6 pri 0 00:00:00

7 pri 0 00:00:00

8 pri 0 00:00:00

Total DS0's Active High Water Mark: 3

Total Calls since System Bootup: 150




Re: RAS Query

We see calls only on the first three DS0s...On the telco switch they can locally initiate a call on any DS0 they choose to...also make sure in "sh isdn service" we see they are not busy.

deb isdn q931 with msec timestamps for a few calls will be useful with mention of time call was attempted (coz we might or might not see it hit the router )

Thanks, Mak.


Re: RAS Query

Hi Mak,

The ISDN 30 has an 0845 number associated with it to give our callers cheaper call rates. It turns out that this number is supplied by a different telco than the ISDN 30. Looks like this 0845 number had a max call volume of 5 calls, the 6th call being returned to the engaged tone. I have upped this volume to match our number of modems, and initial tests prove to be successfull. I still think it is unlikely that we have this many people dialing in at the same time, and my mrtg stats prove this, showing when the service is being succesfully used. Maybe other unknowns are dialing this number.

Anyway, thanks for your help on this