DSP on 3845

[xzjleo2005]

Hi, we have CUCM 7.1 and router 3845 here and now only has one ISDN connected. The router has 4 PVMD2-64 and 2 E1 ports, it has been configured as conference bridge and registerd in the CUCM.

Now we are planning to have another one ISDN, my question is if we need to shut down the conference bridge before bringing up the other one E1 port and pri-group? Does it have any impact to existing production service? Will the router assign the DSP resource automatically?

Thanks. Leo

[paolo bevilacqua]

You can reduce conference bridge a little, and still have resources for the additional E1.

[xzjleo2005]

Any documents can show me how to do that? Thanks.

[Harmit Singh]

Hi Leo,

Since you've not posted the relevant snippets of the config, I'll have to assume that even with 4 PVDM2-64 modules, you cant bring up a new PRI because of the number of conference sessions you have and the 2 current E1 PRIs. The "right" way to do this is to use DSP calculator and check to see if you've got enough DSPs to do what you need to on this router:

http://www.cisco.com/web/applicat/dsprecal/dsp_calc.html

If you want to do it on the fly, then yes, like Paolo even said, reduce the number of conference sessions you may have as it blocks the entire DSP(s) (depending on the number of conference sessions and the codecs listed under the dspfarm profile) whether there is an active conference or not. It will not share its DSPs with PRIs, transcoders, MTPs, etc. Here is an example:

!

dspfarm profile 2 conference

codec g711ulaw

codec g711alaw

codec g729ar8

codec g729abr8

codec g729r8

codec g729br8

maximum sessions 8

associate application SCCP

!

Now if I want to reduce the number of sessions, or even shutdown the conferencing, then you need to do the following:

R2#conf t

Enter configuration commands, one per line.  End with CNTL/Z.

R2(config)#dspfarm profile 2 conference

R2(config-dspfarm-profile)#shut                                                       ----> Conference profile will shutdown. You can configure your new PRI now if you want. However no conference calls will work if this resource is being requested for by CUCM / CME.

Disabling profile will disconnect active CONFERENCING calls,

do you want to continue ? [yes/no]yes

R2(config-dspfarm-profile)#

R2(config-dspfarm-profile)#do show run | sec dspfarm profile 2

dspfarm profile 2 conference

codec g711ulaw

codec g711alaw

codec g729ar8

codec g729abr8

codec g729r8

codec g729br8

maximum sessions 8

associate application SCCP

shutdown

R2(config-dspfarm-profile)#

R2(config-dspfarm-profile)#max sessions 6

R2(config-dspfarm-profile)#

R2(config-dspfarm-profile)#do show run | sec dspfarm profile 2

dspfarm profile 2 conference

codec g711ulaw

codec g711alaw

codec g729ar8

codec g729abr8

codec g729r8

codec g729br8

maximum sessions 6

associate application SCCP

shutdown

R2(config-dspfarm-profile)#

R2(config-dspfarm-profile)#no shut                        ---> You have reduced the conference sessions and should be able to configure the new PRI even now.

R2(config-dspfarm-profile)#

R2(config-dspfarm-profile)#end

R2#

If you dont mind the conferencing going down during business hours, then you can do it, else, it would be best to do it after business hours. I would still say: Go with DSP calculator to make sure you have sufficient resources to do everything you want to on this router. Lastly, please post the configuration if you have further questions on this.

HTH.

Regards,

Harmit.