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Lili

@robi.com.mk

Cisco Interconnect

Dear All,

I'm happy that I found this forum. I need CISCO equipment for Interconnecting with Public Telco. The Telco requires that we have 2 m/bits interface on our interconnecting equipment. The interconnection is based on SS7 protocol and E1 system.

We need the interconnection in order to terminate the calls from IP network using VoIP to the PSTN. Basically, we'll send the calls to the Cisco Equipment from h.323 softswitch, using the g.729 or g.723 codecs, and the Cisco should send the calls to the PSTN.

I would very much appreciate if you help me with selecting the cisco equipment, at least as a starting point, as I'm a bit lost in all those Cisco products.

Putted simple, I need cisco equipment for terminating VoIP calls to PSTN using SS7 and E1 system, support for 2 m/bits interfaces for interconnection with the telco E1 links, support for 60 concurrent g729 or g723 calls.

Thank you so much,
Lili


tubbynet
reminds me of the danse russe
Premium,MVM
join:2008-01-16
Chandler, AZ
kudos:1
You are undertaking quite a big project...
The "interconnection" (as you put it) is not cheap and will require quite a bit of configuration...

Personally, for 60 users, you are going to be pushing the capability of Cisco Unified Communications Manager Express, so I would suggest running a dedicated server with CUCM (same as above, drop the "Express"). This is the "brains" behind your IPT deployment.
In terms of network equipment, I would suggest running a Cisco Catalyst 4509 with two 48-port 802.3af PoE blades. This will allow you to support the high power devices (such as the IP Phone 7971-7975). This will also give you sufficient throughput to handle the core of your network as well as your IPT needs. You will need to enable QoS to make sure that your voice traffic gets tagged as a priority.
You will need a gateway router to hook up everything. I actually would suggest a 2851 or better with the T1/E1 network modules to support your link out. You can also put a little more in terms of the PVDMs that will allow failover to an analog POTS line, SRST in event of a CallManager crash, etc. This router should also be sufficient to handle most of your data traffic needs (especially if you have an ASA sitting behind it so the router won't have to worry about security rules).
Phones are another story and run between $800 - $2200 (USD) per phone, depending on model.

You may want to look at the Cisco site and look at their IP Telephony products page. You can read white papers and implementation success stories...but let me warn you ahead of time...a proper Cisco IPT deployment is not cheap. What I am envisioning for you should run around $100,000 in just product. There are cheaper ways to go (such as not using the 4509, and going with the "express" version) but I don't think that you will be able to support the BHCA (busy-hour call attempt) load that you are describing.

q.


Lili

@robi.com.mk
reply to Lili
Thank you so much for the reply.

Let me explain a little further. We already have a small setup like this:
1. GnuGK as a softswitch (h323 gatekeeper), connected with Radius and Billing server.
3. Cisco 1760 with VIC2BRI

We have ISDN BRI line from the Telco. Basically, there are two copper wires from the regular telephone line that go in NT, and from there the NT unit is connected with Cisco GW on the VIC2BRI interface using a LAN cable. This is a small setup and it works fine. GnuGK accepts registrations and calls from h323 endpoints from Internet and send them to PSTN using Cisco 1760.

However, for a bit bigger setup, we can not use our regular telephone line equiped with ISDN BRI, i.e. not even ISDN PRI which has 30 channels. Telco requires that we must make interconnection with them, where ISDN lines are not used any more, but the interconnection is done directly using SS7 protocol and E1 links.

Therefore:
1. I think that we do not need Cisco Unified Communications Manager Express, since for 60 simultaneous calls GnuGK will do the work. GnuGK is communicating with the RADIUS&Billing server. This is already setup.
2. We do not need IP phones and our own LAN because the calls will come from Internet and from other entities, we'll just route them to PSTN.

My wonder is whether Cisco 2851 equipped with E1 modules and PVDMs will be enough. As I searched cisco.com, I think they say that Cisco PGW 2200 is needed to do the SS7 signaling for interconnection with the Telco. I'm not sure whether the E1/T1 modules will be enough. Telco says we must have 2m/bits interface for each E1 link. We can not ask for interconnection from the Telco if we do not specify exactly what equipment and modules will we use.

I'll be happy if all we need is a Cisco gateway, because we can just send the calls from GnuGK h232 gatekeeper to the Cisco GW, and the Cisco GW will do all the SS7 part.

Please guide me on this.

Thank you very much,
Lili


tubbynet
reminds me of the danse russe
Premium,MVM
join:2008-01-16
Chandler, AZ
kudos:1
Sorry for the misunderstanding, I wasn't too clear on what your setup was like.

The 2mbit/interface is not a big deal. This is the standard speed of an E1 (which is in fact 2.048mbit/sec).

Looking at the link that you have provided me, the PGW would suit your needs. However, I thought that there was a way to run SS7 over an E1 on a VWIC2 that could be thrown into an ISR. However, a search of the VWIC2 cards was a little fuzzy, but it looks like the IP Transfer Point can be thrown into a 2811 and might support your needs.

»www.cisco.com/en/US/prod/collate ··· 203.html

Again, I am a little unsure of your setup (through being unfamiliar with hardware and a lack of knowledge of your existing configuration) so pardon me if this doesn't suit your needs.

q.


Lili

@robi.com.mk
Thank you q. a lot,

Things are more clear to me now and I have better ground to move further.

Lili