Larger Asterisk Deployment Help

[dbaddour]

Hi all,
Looking for help and advice, been working with Asterisk/PBX for 2 years now and provided many support to members on this forum, also I did ask for many. I have a project now due in 2 month; I am the one that wanted to stay with Asterisk/PBX regards of many suggestions from my co-workers to go with something else, my argument is Asterisk/PBX will work for us, great system and support what we need. Finger crossed.
My project is like this, I need to install Asterisk/PBX in our new location with 35 users, and we have 8 analogue phone lines coming into the building. Would like to use the most of this system so the user would not have to wait for a line, keep getting busy signal when all lines on use. Also we have to other offices thru out the country, would like the use to dial an extension in between the offices instead dialing the full #. I have a server (hardware for it are ready) what do you suggest to use for analogue card installed to support it all? Any special installation needed to make this easy to implement, and test it before it gets into production? Should I use a router as DHCP/DNS? If so what type of router you suggest? How should I go with the extensions to dial other offices by extension number?
Always your help is much appreciated and hope I can have some valuable suggestions to get this going as early possible.

Thank you

David

 

[atsak]

I recently deployed something similar for 80 users.

1. I used the sangoma card for the trunk lines. Works great.
2. Setup an account with a SIP provider and send outbound calls via SIP trunks, and use inbound via the trunk lines. Saves the busy signal problem.
3. For other offices to dial by extension you either have to setup an asterisk server in each office and use IAX or Dundi trunks, or you can setup a dial plan so if people dial a prefix (perhaps XX where XX is unique for each office) plus the office extension and the dial plan rewrites the XX portion to include the external office.
4. I prefer keeping DNS / DHCP on a server so it's easier to set the t*f*t*p server if you use an endpoint manager. If you use a router try to find one that supports setting the options for t*f*t*p (66 and 150 if memory serves) in case you want to use that feature later. I can't tell you what to use; I have used Juniper, Cisco RV042/082, Dlink gaming routers and others. The Junipers are the hardest to configure but are real firewalls . . . the others were fine too. Look at some of the pfsense appliances as well those seem to work very well also and are inexpensive.

 

[spot]

That is quite a project

First need to understand project more.

Do the sites you want to peer with ( 3 digit dial etc) have vpns (ipsec, etc) between them?

What type of internet at each location and speeds

What are the existing routers/models at each location

What type of phones are you deploying?

Will all phones attaching to the system be local with phone system? Any remote? Any at other sites?

Are there existing asterisk phone systems/ or systems that support iax or sip trunking at the remote locations??

Why are you using analog lines opposed to sip/iax trunking? (I setup both just curious why analog has been chosen?)

spot

 

[dbaddour]

I know, that is why i like to gather much info possible before starting testing or ordering any hardware.
- yes we have VPN active between the locations,
- we 10 burst 10up and 10down
- we are using the SME as geteway/router
- i have the Mitel 5224 ip/SIP phojnes
- they are local, remote will be nice
- i will be installing the same at the remote location, i can do that test now between the 2 offices before we move into one location.
- that what we have for now analog phone lines.

 

[Stewart]

We have some deployments that actively utilize VPNs in several ways.

Our estimation is that if there is expected to be more than 5 concurrencies or more than 10 extensions at a site, it's more sound to have a server at each location and then you connect server to server for inter-office dialing. It's not so much the load on the server, but on the VPN that may have problems. And it's not throughput, it's just the number of packets the router must sift through since RTP is very intensive.

If there are fewer than 10 phones or 5 Concurrent phones, than a VPN will work just fine. If you find problems with voice quality but bandwidth is fine, then encryption aggressiveness and SPI may be too much. Just watch your number porting. Remote offices may need a number local to them. That'll require some extra planning.

In all we've found that using analog lines is much more stable than VOIP, though it may be the ITSP we've hitched ourselves to.

We use Linksys RV042 and RV082 routers with SPI turned OFF. IPSec VPNs are stable and RTP is processed fine. There are no QoS setting specifically for VOIP so it's not exactly VOIP aware, but you're using analog lines and only sending SIP over VPN so you're fine.

As for handling your analog lines? We use Grandstream the most, but they need to be rebooted every so often and need to reboot with every change. Luckily the reboots are only about 15 seconds. They have a GWX-4108 that should work for you (I think that's the model) since it has 8 ports, but we have a difficult time with port 1 so it's really only 7 usable. If one of your 8 analoge lines is going to fax then it'll be fine. If you're needing more then there is a 24 port version available. We do it to hit a pricepoint that our clients need so realize it's the cheapest ones out there. Audiocodes and Patton are probably much better.

Good Luck!

 

[jmullinix]

David,

There is more to be considered here. If your folks are currently waiting on outside lines, then you will need more analog trunks. I use a rule of thumb of 4 extensions per trunk. For sales offices and medical practices, I change the rule to 2 extensions per trunk. Your office will need a minimum of 9 trunks, using my calculation and more if it is a medical practice or a sales office.

Having dialing between branches is easily implemented with an IAX trunk between the boxes or using Dundi. Dundi is more secure, but the initial setup is more difficult.

I would not use Grandstream anything in an implementation this size. Stick with Sangoma for your TDM cards and either Snom, Polycom or Aastra for your desktop phones. Your life will be more pleasant if you do that

I have put several systems like this together. If you have questions, feel free to call.

 

[Stewart]

Our line calculation is similar. Our general formula is:
ROUNDDOWN((#Extensions)/4+3
so your 35 extensions be 11 lines. It's roughly based on Shoretel's recommendations for the average office.

I also agree with the phone recommendations. Aastra phones have good voice quality and are very flexible. Polycom phones sound great but dont have the same level of useability. I haven't used Snom, but they look and feel good. Grandstream phones? Eh. I have a video phone for testing, but they're tempermental.

Never used a Sangoma card as I prefer the idea of having the Gatway separate. Now, if only Sangoma could use their cards in a gateway. A modular gateway is something I could go for!

 

[jmullinix]

No problem. Build a PBX and put a Sangoma card in it. Sip or IAX trunk it to your main PBX and voila, you have a gateway.

 

[dbaddour]

Ok, first of all thank you for all of your replies. Going forward with this, i manged to get a IBM X345 server and Digium (1TDM808BF ) iI will be using the Mitel IP phones 5215 and 5224 Dual mode. Reason for going for all these is that after the considilation of both offices we have these remaining and better go for a use. i have great experience with these phones, and the server. the Digium card i have installed 2 other previously and worked fine. my next concern is the software and get all to work together. Here is what i have in mind.
- use the latest version of Asterisk/PBX with Dahdi. i will attempt the setup when i receive the card and hope all be fine with the configurations
- Since I am using Dahdi, How chalaging is it to make the connection between the offices? or it is easier to use router for routing between the subnets? using the VPN? if IAX is easier i have no worries about security since it is internal and we have great firewall and security i place. How to set up the IAX to make 2 office connection? easy?

Thank you all again

 

[blanchae]

for the IAX trunk, follow these almost bulletproof instructions. Make sure that you download and use the excel spreadsheet, just fill in the green areas. The IAX configs for both servers will be automatically configured, you just have to transfer the configs to the servers.

 

[dbaddour]

Sweet, Nice to hear from you again blanchae.
one concern, the 2 servers are going to be in seperate locations, thereoff each will be running on different subnet one is 192.168.5.XX and the other 192.168.1.XX. folowing the bulletproof instruction will that need an routing in exist or IAX2 should take care of it as long VPN connection exist.

 

[blanchae]

If you can ping from one subnet to the other than it will work. If it can't then you have a routing (network) issue and not an IAX2 trunk issue.

 

[dbaddour]

I will be making that route between the 2 subnets.

Any one have an experience with this card 1TDM808BF? if so any special suggestions before installing it and easy proccess to have it to work with my new system??


Thank you

 

[dbaddour]

Eugene,

Following those instruction, I end up with where that file can be saved on the server?

Please and thank you.