Configuring Cisco router as a PSTN simulator

[Nightwolf_82]

This message was edited as the PSTN config is correct.

[Nightwolf_82]

The first issue I faced with is that I can't configure 30 channels on each E1 PRI group on PSTN-RTR. I get the error below:

% Not enough DSP resources available to configure pri-group on controller E1 0/1/0
% The remaining dsp resources are enough for 2 time slots.
% For current codec complexity, 2 extra dsp(s) are required to create this voice port.
 

Will it help if I change PVDM16 x 2 for PVDM64 x2 or I have to reduce the number of channels on each E1 PRI group on each router?

[Jaime Valencia]

That is completely expected, you need 1 channel per DS0 and you only have 32, yes, you'll need more DSPs if you want all channels to come up, or use less channels, whatever you choose

As for the side that will emulate the PSTN, also add:

isdn protocol-emulate network

Under the serial interfaces. Then just build your cables for T1

[Nightwolf_82]

This message was edited as the PSTN config is correct.

[Nightwolf_82]

This message was edited as the PSTN config is correct.

[Nightwolf_82]

Hi guys,

Just got a question regarding international access code and trunk access code. 

If we have a deal with real PSTN then such things like international access code and trunk access code are predefined by institutions that governs public telephony. 

But how international access code and trunk access code are defined on PSTN simulator? If I need to use 0 for access outside of the company or 0011 for dialing international number, how it should be configured on PSTN simulator?

Thank you.

[Nightwolf_82]

This message was edited as the PSTN config is correct.

[Nightwolf_82]

Hi guys,

It is know that in CCIE Voice Lab usually 3 sites are used. 2 sites in USA and 1 in UK. In The USA ISDN switch type is primary-5ess, and in Europe primary-net5. 

I tried to configure both ISDN switch types on PSTN simulator but no luck. It seems that only one ISDN switch type can be configured on a router. 

Is there any way to have a router to be configured with ISDN switch type is primary-5ess for one site and the same router to be configured with ISDN switch type primary-net5 for another site?

Thank you.

[Nightwolf_82]

Hi guys,

Here is my inventory for voice on routers.

HQ:
VWIC2-2MFT-T1/E1 (1st E1 for voice circuit; 2nd E1 for Frame Relay circuit).
PVDM2-16 x 2

BR1:
VWIC2-2MFT-T1/E1 (1st E1 for voice circuit; 2nd E1 for Frame Relay circuit).
PVDM2-16 x 2

BR2:
VWIC2-2MFT-T1/E1 (1st E1 for voice circuit; 2nd E1 for Frame Relay circuit).
PVDM2-16 x 2

PSTN:
VWIC2-2MFT-T1/E1 (1st E1 for voice circuit; 2nd E1 for Frame Relay circuit to HQ).
VWIC2-2MFT-T1/E1 (1st E1 for voice circuit; 2nd E1 for Frame Relay circuit to BR1).
VWIC2-2MFT-T1/E1 (1st E1 for voice circuit; 2nd E1 for Frame Relay circuit to BR2).
PVDM2-16 x 2

When I configure E1 voice circuit to HQ everything is fine. As soon as I configure E1 voice circuit to BR1 I get this error when try to configure full pri-group timeslots on PSTN router.

% Not enough DSP resources available to configure pri-group on controller E1 0/1/0
% The remaining dsp resources are enough for 2 time slots.
% For current codec complexity, 2 extra dsp(s) are required to create this voice port.

It seems that PVDM2-16 x 2 is not enough on PSTN router. Could you please give an advice if PVDM2-32 x 2 or PVDM2-62 x 2 would resolve this issue. 

Thank you.

[Nightwolf_82]

Hi guys,

I forgot to ask the most important question about Cisco router as a PSTN simulator. As you probably know in CCIE Voice topology there are three sites (HQ, BR1 and BR2) with HQ and BR1 in the USA and BR2 in UK (as far as I know). For testing purposes CME can be configured on PSTN router to test calls to and from sites and PSTN router. However, my question is if it's possible to test calls between all three sites with PSTN simulator?

Thank you.

[Terry Cheema]

Yes you can test connectivity to/from PSTN from all sites.Its just a CME registered phone and you configure PSTN number like 911 or other PSTN numbers on the different lines of that phone. You just need appropriate dial-peers on the PSTN/CME router to reach each individual site.

-Terry

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[Nightwolf_82]

Hi Terry,

Thanks for your reply. I know that it's possible to call on PSTN router using CME on that PSTN. However, my question is if it's possible to call from HQ site to BR1/BR2 or from BR2 to HQ/BR1 and etc via PSTN simulator. 

Thanks. 

[Terry Cheema]

No Probs - but you mentioned CCIE V lab - so assuming you have CUCM for on-net calling why do you want to do that.

-Terry

[Nightwolf_82]

Actually, just for personal interest. I setup my own CCIE Voice lab and started to configure it, but this question always bothered me. If the idea of CCIE Voice lab to setup call flows to and from site and PSTN router or calls between sites can be setup as well. 

[Terry Cheema]

Whenever you have IP connectivity you will want to route calls over IP (hence VoIP)

When you have CUCM - all your phones HQ/BR1/BR2 are registered in there and CUCM will router them over IP instead of a PSTN call.

If you have a CME - then also since all your sites have direct IP connectivity through Frame Relay - you will setup dial-peers for example extensions starting with 3 to point to BR1 router, starting with 4 to BR2 router - routing over IP.

But if CUCM fails or is at a different site and WAN link is down your site is operating in SRST - then you can configure the dial-peers on your local router to send the calls (for other sites) to PSTN router and on PSTN router you will have dial-peers to route them to respective site over the PSTN E1 and not the frame relay.

So in short can be done.

Once you advance in your study things will start to make more sense.-Terry