Total Beginner to IP telephony - Any help please? 2

[nitrokid]

Hi all,

I've been asked to start reading up and learning about IP telephony for a proposed implementation in 2009. I am totally new to the arena and have a few questions about the infrastructure.

The structure we will have is that we have a central headquaters with 6 branches connecting to it on an MPLS network. We want to run the telephony on its own seperate dedicated infrastructure and I am initially thinking that the HQ will host the IP PBX which connects to the PSTN for external calls. Internally, at the HQ we have a set of network switches that the end telephones connect to and that the PBX has a link to. From these either these switches or another interface on the PBX, there is a link to the firewall/router for access to each of the branches. At the branches, there are switches again that the telephones connect to, and a link to the branch firewalls that connect back to the HQ over their MPLS links. Very similar to a regular data network is how I have it in my head. Is this generally how it works? Is there any equipment that I am missing out, either at the HQ or the branches?

Any pointers to beginners guides or other documentation that discuss the physical network structure would be much appreciated. Also, recently being on the CCNA curriculum, I have heard alot about Cisco's new courses and am think about getting a book in. Which is the best curriculum to get a book about, CVoice or CCVP?

Many thanks

 

[Silverblade]

This is the right way to do it. I can't think of any extra's you'll need.

CVoice is a nice basic (and part of ccvp)
I'm suggesting that you are looking to implement the cisco callmanger than ipt1 and ipt2 can be a usefull course. (also part of ccvp)

Qos (wich is again part of ccvp) can be usefull. but only when you will intergrate the voice into you data network.
But you say that you will serperate data and voice, you won't need it.

Good luck with the implementation

 

[Sympology]

Ok seems ok.

First up, you need to check that your firewalls are VoIP "friendly". They have a nasty habit of messing up voice. If you NAT, you may need to look at STUN servers.

Next QoS end to end. MPLS is great, but you will need QoS set up on it. Many carriers charge extra for this. you may be lucky and it work with out it, but you don't want to rely on luck.

One huge whole you have.
Redundancy.
If you loose the PBX are you willing to loose every single phone in the business? thought not. Look at this.
Same goes for your network. People are ok if they loose connection to email for an hour, put phones are a whole different story.

You could set up a mini lab to test your links. I have 3CX set up on my laptop. A simple, free VoIP PBX, but useful for going to sites and testing connections etc. Many others are out there.

A fantastic tool for testing is SIPp. Use with caution, you can easily take down a network or PBX with this!



Only the truly stupid believe they know everything.
Stu.. 2004

 

[nitrokid]

Thats great. Don't worry, redundancy will be factored in totally but I'm mainly just trying to get knowledge of the core components right now and how a physical voip structure is built, and it seems like I was on the right track with your replies

 

[rtfmdude]

Nitrokid,

You have the right basic idea; the whole concept around VoIP is that you should be able to continue to use the existing enterprise-grade data network to run the phones. There may be some upgrades necessary on routers to interconnect to the PSTN, but I've actually spoken to a few enterprises here in Houston that are trunking to ATT over SIP: no TDM interfaces here.

First, I would get some product/technology knowledge before you go and spend any money - i think this is a cool video that shows how cisco deployed voip internally:

http://tools.cisco.com/cmn/jsp/index.jsp?id=47668&redir=YES&userid=(none)

Here's the Unified Communication/Voice area on the Cisco Learning Network (totally free) take a look here, too:

https://cisco.hosted.jivesoftware.com/docs/DOC-1348

Also, here's the certification path for the different technologies, perhaps you should start with the CCENT?

https://cisco.hosted.jivesoftware.com/community/certifications

Hope this helps!

 

[mattKnight]

Whilst I wouldn't argue against Cisco in all circumstances, there are a number of other manufacturers and solutions which may be a better or at least as good a fit.

The training from Cisco is, obviously, tailored to Cisco IPT and will imply that Cisco is the only game in town.

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[jneiberger]

I agree with Matt. Look at more options before you decide on Cisco. Is this a brand new installation or is this an upgrade from an older system?

Depending on your requirements, I would also look at Avaya, Shoretel, Mitel and Nortel.

To be honest, if you just need phones, voicemail and basic unified communications with redundancy, I'd go with Shoretel. Easy to install, super easy to manage. You won't need two weeks of paid training to understand the system.

 

[mojoputter]

...and if you are adding this system to a current data network I would recommend a network assessment just to make sure your existing network can handle the traffic, but if your using a new network just for phones then there would be ne need, but then that would defeat the purpose of an VOIP system. You purchase a VOIP system to consolidate data & telcom so why would you want to manage virtually 2 networks..?

We use Avaya IP phones, our PC's connect right to our phones and everything is on 1 network very easy to manage.

 

[mattKnight]

>I would recommend a network assessment...

Mojoputter - a good point! I'd go further though, a network assessment is a requirement not an optional extra

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[nitrokid]

Hey all,

Thanks for the replies. I have not come to any conclusion about which vendor to go with. The only reason Cisco was brought up is because they are the only vendor I know of with a prominent IP telephony curriculum available in the UK right now and I was wanting peoples experiences of whether they could learn VOIP fundamentals through the books for those courses...

We are planning to run the telephony on its own dedicated network, where the only time media is shared by data and telephony is on the WAN between branches, which will be 10mbps MPLS to each branch. These are small branches so I anticipate no problem. We want to run seperate rather than consolidate due to high utilisation bursts at random points throughout the day on our HQ LAN, to localise and limit any issues that may arise. Also, it would be alot easier for us to administrate this type of setup. All our branches have their seperate PBXs right now and every time any administration needs doing, we have to go out (all infrastructure support is based at the HQ). Its a very old PBX and remote support is not available. So if we are going to upgrade, better to IP for ease of management and also flexibility in the future.

As I said, I'm just trying to mainly get my head around what equipment is needed generally for an IP telephony infrastructure

 

[jneiberger]

If you can find it, I would recommend an older Ciscopress book called Integrating Voice and Data Networks by Scott Keagy. It is not Cisco-specific and teaches you a lot about what you'll need to know. It's a superb book, but hard to find now. And I'm definitely not selling my copy of it.

Most of Cisco's other courses and books are more specific to their technology, not VoIP in general.

 

[rtfmdude]

Nitrokid,

It's not necessary to run separate infrastructure except in the most extreme of circumstances. Proper quality of service (QoS) configuration will prioritize the VoIP traffic even during periods of heavy utilisation without missing a beat.

Does anyone know of a public place where i can drop some pdfs and stuff? I'm not familiar with how to use rapidshare, etc and would appreciate a recommendation.