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New Member

ip telephony network design

I have 2 2651XM cisco routers with 2 Fast ethernet interfaces and cisco call manager express installed in each one.

I have a primary line conection E1

I need to configure a network with 72 telephones and 10 Fax machines.

My question is:

Which E1 interface card I need to integrate in the routers and use it as a gateway to the PSTN?

I think each router only can handle 52 telephones, so It'd be possible to use the 2 routers for dividing the 72 telephones and 10 Fax machines?

I suppose I can install 1 E1 card in one router and the other router without E1 card.

Which configuration do you recommend?

2 ACCEPTED SOLUTIONS

Accepted Solutions

Re: ip telephony network design

Check this matrix

http://www.cisco.com/en/US/products/sw/voicesw/ps4625/prod_installation_guide09186a00805f5908.html

When I said 48 phones, that is the total number of phones that can register to the CME at any time (in fact you may be able to go up to 52 phones)

You can find install guides here.

http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_documentation_roadmap09186a0080189132.html

HTH

Sankar.

PS: please remember to rate posts!

Re: ip telephony network design

With CME you can use either FXS ports on the router and run cable to where the fax machines are. This is a very clean solution. I prefer doing this. If you have higher density of fax machines, you may use a VG224. VG248 is not supported with CME.

You can also use ATA 186/.188 with fax machines but as of CME 3.x only H323 image of ATA 186 is supported with cme, which means the phones attached to ATA are not considered as ephones. ATA works as a H323 voip gateway with CME. I will have to check if SCCP image for ATA is supported with fax machines with CME 4.0. If you use ATA for attaching analog phones you may use SCCP image (or H323 image). For analog phones with SCCP image on ATA, you will need to create ephones and ephone-dns, just like any other IP phones.

Also note that some newer fax machines (high speed) cannot work with ATA as ATA is limited to 14.4 kbps speeds.

Hope that makes sense

Sankar

PS: please remember to rate posts!

12 REPLIES

Re: ip telephony network design

With CME 4.0 you can run HSRP between the two boxes. Its ideal that you use two E1s, 1 on each, because if a router (active) fails your E1 also goes down with it.

You may use VWIC2-1MFT-T1/E1 or VWIC-1MFT-E1 card on each router.

With 2651 you can have only 48 phones per chassis. I may recommend using 2851 if you want redundancy between the two chassis (each supporting 96 phones at smae time).

Also at this time there is no redundancy available for CUE.

HTH

Sankar

PS: please remember to rate posts!

New Member

Re: ip telephony network design

Thank you very much for your response, but I cannot buy a new cisco 2851, so I have to try configure it with the 2 cisco 2651.

when you say 48 phones per chasis, are you saying simultaneous calls? or telephones supported?.

Can you help me how I can upgrade to CME 4.0?

regards

Re: ip telephony network design

Also please be aware that 2600XMs will be EOL soon (but not End of support) as there is a wide installation base. The 2800 ISRs are the right way to go at this point.

Re: ip telephony network design

Check this matrix

http://www.cisco.com/en/US/products/sw/voicesw/ps4625/prod_installation_guide09186a00805f5908.html

When I said 48 phones, that is the total number of phones that can register to the CME at any time (in fact you may be able to go up to 52 phones)

You can find install guides here.

http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_documentation_roadmap09186a0080189132.html

HTH

Sankar.

PS: please remember to rate posts!

New Member

Re: ip telephony network design

thanks again.

On the other hand, can I treat a Fax machine as 1 telephone more an ATA 186?

Is there any problem or special requirement for FAX transmision in CME ?

regards

Re: ip telephony network design

With CME you can use either FXS ports on the router and run cable to where the fax machines are. This is a very clean solution. I prefer doing this. If you have higher density of fax machines, you may use a VG224. VG248 is not supported with CME.

You can also use ATA 186/.188 with fax machines but as of CME 3.x only H323 image of ATA 186 is supported with cme, which means the phones attached to ATA are not considered as ephones. ATA works as a H323 voip gateway with CME. I will have to check if SCCP image for ATA is supported with fax machines with CME 4.0. If you use ATA for attaching analog phones you may use SCCP image (or H323 image). For analog phones with SCCP image on ATA, you will need to create ephones and ephone-dns, just like any other IP phones.

Also note that some newer fax machines (high speed) cannot work with ATA as ATA is limited to 14.4 kbps speeds.

Hope that makes sense

Sankar

PS: please remember to rate posts!

New Member

Re: ip telephony network design

good answer, but I have a problem with cabling until the FAX machines and connecting it to the FXS cards.

My network is composed of several buildings linked by wireless links, so I don't have the possibility of use FXS gateways to the FAX machines.

So I need to try find some ATA or something like that to connect the FAX machines.

Is there any specific device from Cisco to connect FAX machines or for doing as FAX machines?

Re: ip telephony network design

So looks like your best option is ATA. ATA 186 costs < 200 $ list, and has two ports per box. You can connect up to 2 fax machines, or 2 analog phones or a mix of both (1/1) on these ports. If you get ATA 188 you can daisy chain a PC through a second ethernet port, just like IP phones do.

ATA is a Cisco product. Check its datasheets here.

http://www.cisco.com/en/US/products/hw/gatecont/ps514/index.html

Re: ip telephony network design

Based on this link

http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_configuration_guide_chapter09186a00805b21ba.html

Its confirmed that CME 4.0 doesnt support ATA in SCCP mode for fax machines (it does support ATA in SCCP mode for analog phones).

HTH

Sankar

PS: please remember to rate posts!

New Member

Re: ip telephony network design

but is not clear for me, if you read here :

"For a Cisco ATA that is registered to a Cisco Unified CME system to participate in fax calls, it must

have its ConnectMode parameter set to use the same RTP payload type as the Cisco voice gateway

that is performing the fax pass-through. Cisco voice gateways currently use standard payload

type 0/8, which is selected on Cisco ATAs by setting bit 2 of the ConnectMode parameter to 1. For

more information, see the “Parameters and Defaults” chapter in the Cisco ATA 186 and

Cisco ATA 188 Analog Telephone Adaptor Administrator's Guide for SCCP (version 3.0)

So it's possible to have remote ATA's for FAX machines using correct firmware and changing a bit in the configuration? or you need the ATA and the FAX gateway or FXS interface card too?

Excuse me but it's not clear for me but very important.

Re: ip telephony network design

Connectmode parameters are available in both H323 and SCCP mode.(Not sure if this is a typo on the document) I have had issues with SCCP / fax and ata before (CME 3.x, never did a 4.0 implementation with ATA/fax/SCCP mode). I will test this in lab here soon and see if there are any issues.

New Member

Re: ip telephony network design

thanks in advanced.

I will post another public post asking it, perhaps anybody knows it and can explain it to us.

I will try it and will tell you, i hope the same of you.

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