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Considering Cisco VoIP Phone system replacement

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RichardParry

IS-IT--Management
Aug 28, 2002
91
GB
We will be moving to new premises at the end of November and to save call costs and line rentals we are looking at converting from a Panasonic PSTN 6 line (18 extension) PBX system. We don't want to install any analog telephone ports in the new property. I am relatively new to the VoIP technology but have been advised that Cisco VoIP technology is the most common and has the most features. We are on a budget, but would prefer to do things correctly the first time round. Although I will speaking to a number of local telco system suppliers who specialise with Cisco VoIP systems, I was wondering if you guys could lend a hand.

I want to purchase 10x 7960 phones (please explain the difference between the 7960 and the 7960G phone) and I believe I need a Cisco Call Manager server to run all the call logging, call management, music on hold, voice mailbox's, call transfer etc. We currently have a Cisco 2600 series XM router (can't remember the exact model) with dual ADSL lines bonded to one virtual connection (to double upstream and downstream) and a Watchguard Firebox firewall doing the NAT. We have a range of public IP's and the firewall is assigned one of these IP's on the external WAN interface. I envisage that I could also use one of these public IP's on the call manager server?

How does the call manager server route calls outside the network? Would we need to source and pay for an external VoIP gateway provider? Can any SIP capable gateway work with the Call Manager system? We currently have 2x telephone numbers shared across the 6 lines, 3 for each company in-house (one is a sister company), is this also possible with most VoIP providers?

I see quite a few cisco router's fitted with FXO interfaces, what is the purpose of this?

Thanx!
 
Usually the FXO ports in a router are for interfacing with the PSTN. Most businesses that have deployed VOIP phone systems still use traditional voice services from the telephone company to get calls to and from the outside world. I have talked with several providers about IP based trunks, but I am still not convinced that the technology is sound. Everything works great in theory, but you never know how friendly the internet is going to be to your voice packets from one day to the next. Voice streams are very susceptible to degradation from packet delay and packet loss. You can control things on your local network to avoid delay and loss; but both of these are out of your control when it comes to traversing the public internet. We have sites on our CallManager system that are connected via VPN over the internet and I can tell you from experience that one day it will sound great, but the next day you may have to hang up and use a cell phone it sounds so bad! I love my Cisco phone system and VOIP technology in general, but I won't be switching to an IP based PSTN connection any time soon.
 
Thank you for the reply, however I am a little confused, all of the setup's I have seen with an FXO module used is for just a single FXO module, surely meaning only one PSTN telephone line for incomming and outgoing calls? The purpose of getting VoIP would be to remove the additional 4x phone lines that we are using at the moment, so we don't have to pay for line rental and higher call charges. I would be hard pushed to find a Cisco router capable of handling 6x FXO cards? I am assuming here, due to the RJ11 interface that an FXO port is a single line.
 
The Cisco VoIP Deployment is more a replacement for the traditional copper lines inside the building for your internal PBX and phones (you don't need to run seperate lines for phone and data). You still to have some interface to the PSTN. This is usually a PRI or POTS connection. You can definetly find a router that supports 6 POTS lines or more. We have a 1760 (older) with 6 POTS lines in our office (3 - 2FXO modules). As AdmanOK stated there are options to skip traditional PSTN connections, but I have not read anything that says they are ready for prime time and they add a layer of complexity in integrating your Cisco VoIP with their equipment.

 
For the size of your installation, CallManager Express may be your best bet. CallManager Express will run on a Cisco Router platform and with the right router can even house your voice mail system within. You can definitely get a router platform to handle all your needs, FXO count, CME and Unity Express. A 2811 router can provide over 16 FXO ports or 12 FXO and a WAN port plus house the voicemail system. You can keep the 2600XM doing what it's doing. CME/UE on a router/gateway would be a LOT cheaper than 2 standalone servers, CM and Unity VM.
The oproblem with going all IP trunks is, how will you handle 911 calls? An IP trunk provider may have the answer, I've never had a customer want to do this.
 
What is the reason you would like to move from Panasonic system?
 
Thank you for the replies so far. As I said, I want to move from our current Panasonic system as it uses PSTN telephone lines (6x lines), and the line rental and call costs are pretty expensive. I was under the impression that although there may be a cost outlay for the Cisco VoIP kit, the benefits of a) not having to wire the building with telephone points b) cheaper calls and c) no PSTN line rentals.

With regards to some user's comments concerning routers handling multiple FXO ports, there's no benefit to us if we are routing IP phones through our network then to a PSTN line than running our current PBX system. In fact, if that's how VoIP works, what's the point in it, if you can only benefit from digital IP calls in the office? Unless you have remote offices, I can't see, based on what some have said, there is no point in IP communications, but yet VoIP is becomming more and more popular by the day.

With regards to the 999 (I am in the UK) calls, since we will have 2x PSTN lines into the building, on the bonded ADSL, one will be used for a fax machine, that can be used for dialing emergency services.
 
If you don't have any PSTN lines, how do you expect to place calls to people without IP phones, particular users on the PSTN?
 
I thought that was all done with a VoIP gateway provider? I have used a VoIP provider in the UK with a Cisco SIP phone, called SIPGate, they provide the VoIP routing and IP to PSTN conversion. Their call charges is far cheaper than the PSTN landline equivalent (British Telecom). If we have to purchase a more expensive router and the same number of phone lines as we currently have there's no point in even considering VoIP - and if that's the way VoIP works I am surprised anybody is interested in it.
 
While you are correct, some installations require the PSTN connections it sounds like you won't. Where the real savings in your's and other installations is in Moves, Adds and Changes time and charges. If John Smith moves into Sally Jones old office with a traditional PBX, you need to either reprogram or re-wire the connection. With VoIP, you just carry the phone and plug it in with the PC. In the US a Telco provider site visit may run a couple hundred $$ and you have to schedule sometimes days in advance. It doesn't take too many of these visits to start making your ROI look good.
 
I will help on an early question you had first
please explain the difference between the 7960 and the 7960G phone

The G at the end means the phone is capable of Gig LAN Speeds, so a 7960 has a 10/100 3-port imbedded switch, and the 7960G has a 10/100/1000 imbedded switch.

On your other issues of a gateway, I agree with pndscm about it being possible. I personnly feel the biggest saving and place for VoIP is in the elimination of private network connections. In your situation, you have 1 office and a few phones. Without some form of low cost VoIP gateway, there is no real cost savings to you.

Now imagine a company with 100 offices, all spead out a geographic region, and all of those offices connected together for voice and data on seperate networks. Remove the voice connectivity and run it over the data network, cost savings becomes huge. This does not even begin to go into the features like mobility and the reduction of MAC's. There will always be a few areas you need to address, like making sure every drop is wired if you want that type of relocation option, but how much is that compared to the cost savings?

The real savings is in what you have today that can be eliminated or moved on to another service you have today, with little cost to the existing service.

Hope this helps,

Scott M.
 
You might want to read up on the 7960g phones there.. The 'G' does not mean gigabit. It means 'global' so that they can make 1 phone and have it work anywhere in the world language wise, etc...

Only the 7970G-GE has gigabit ethernet.


BuckWeet
 
Duh,

Sorry about that. I should read the post a little more clearly next time.

Bad Scott
 
In your case before deciding to move to VoIP find VoIP providers, get their service pricing, and see how much you'll be saving over PSTN lines. Like you said it may not even worth moving to VoIP.
 
Talk to your solution providor, get references from someone who they have done for them, what you are looking for.
The assumption that Cisco is the only solution for you is very narrow minded, especially if your business depends on it. The solution is only as good as the providor, check out the market, and see what others offer. Also, do not take someones opinion that Cisco offers more features than others. Find the features you need, then compare solutions, the features offered do vary by the solution providor.
My last word on this, stay away from anyhting windows based for obvious reasons.
 
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