Configuring an 3845

[KDSM]

I'm trying to configure a 3845-MB as a fall back device to the one that is currently running in production and I can't seem to get some of the configuration to work.  I started out by making a copy (to a text file) of the running config and just applying it to the back up device. That work with the following exceptions.  On voice-port 0/2/0:23 and voice-port 0/2/1:23 I can't get this config line to apply "echo-cancel coverage 64".  I have enabled echo-cancel on both ports (echo-cancel enable) but get an error when trying the other command  "Invalid input detected at '^' marker" it's pointing to the 64.  There are 4 other voice ports that have this configured. 

The other configuration issue I'm having are with the following lines. 

call-manager-fallback
secondary-dialtone 9
max-conferences 8 gain -6
transfer-system full-consult
ip source-address 192.168.1.2 port 2000
max-ephones 450
max-dn 800 dual-line
default-destination 2100
voicemail 1000
call-forward busy 1000
call-forward noan 1000 timeout 24
moh music-on-hold.au

I don't get an error on the first command line but all the rest show up with invalid input detected line.

As back ground I was asked to support this device and other switches and router when the employee that normally does it moved to a different company. So any help would be greatly appreciated. 

[Georg Pauwen]

Hello,

I am afraid you are stuck. The 3845 is end of life as of 2011. So it is a very old device, most likely with a very outdated IOS version that does not support all commands. What is the production device ? Can you post the output of:

sh ver

from both ?

[KDSM]

Hi;

  Thanks for getting back to me so quickly.  Attached are the versions from both devices.

[Georg Pauwen]

Hello,

odd, since the backup router has (almost) the identical IOS version. Maybe you can do the following: erase the entire configuration from the 3845 backup router (using the 'wr erase' command), then reboot the router, and enter everything manually (hopefully the configuration file is not too big)...

[KDSM]

Hi;

  the configuration is quite long but if this works it will be worth the effort. 

[Georg Pauwen]

Give it a try. Another option, thinking about it, would be - if manually entering everything still doesn't work) - to copy the IOS from the production to the backup router.

[Georg Pauwen]

Also, the backup router seems to have less memory...not sure if that is related...

[KDSM]

So this problem has popped up.  when entering 

ip ssh time-out 60
ip ssh authentication-retries 2
ip ssh version 2
I get the error "Please create RSA keys (of atleast 768 bits size) to enable ssh v2.

[Georg Pauwen]

Hello,

looks like you manually need to create the key:

DIS-MDF-MO-CR#conf t

DIS-MDF-MO-CR(config)# crypto key generate rsa 768

[KDSM]

Just as an update entering stuff by hand didn't help....

[Elliot Dierksen]

Perhaps the DSP modules in this router don't support that length of echo cancellation coverage. On the voice port, try "echo-cancel coverage ?" and see what options it gives you.

[KDSM]

when adding that command the response is "Incomplete command" however if I do echo-cancel coverage 64 no error is returned.

also I have 4 other voice ports that the command shows were it doesn't 

voice-port 0/0/0:23
echo-cancel coverage 64
!
voice-port 0/1/0:23
echo-cancel coverage 64
!
voice-port 0/2/0:23
!
voice-port 0/0/1:23
echo-cancel coverage 64
!
voice-port 0/1/1:23
echo-cancel coverage 64
!
voice-port 0/2/1:23

thanks for you input.

[Elliot Dierksen]

If you do a "show inv" in the new and old router, is there a difference in the number of DSP modules available? Your config snippet these shows 6 PRI interface which would require at least 138 DSP channels.

[KDSM]

I did the show inv on both and they are not the same.  The back up unit is missing and PVDMII and has a MFT-EC-64 that's not in the other unit.

I have attached text files for both units.

[Elliot Dierksen]

Assuming low to flex complexity, you can create (6) PRI interfaces with 192 PVDM channels available. The MFT-EC means the card has a hardware echo cancellation module. It varies by platform and hardware as to if it available and how long coverage it can support. I think "echo-cancel enable" is default on a voice port. If the hardware supports it, entering " echo-cancel coverage ?" at the voice will tell you what length of coverage your hardware supports. This is an example of echo cancellation enabled in a 2911 voice gateway.

voice-port 0/0/0:23
 echo-cancel coverage 64