Analogue VS ISDN for Asterisk-based PBX

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rm501

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I was wondering if anyone could please advise.
I'm building a new call center. Very small, 6-8 agents.
I'm going to use Diguim cards with trixbox.

I dont know whether to use analogue (POTS) lines or ISDN lines. Require (6-8 lines)
What are the benefits of ISDN?
Is it more reliable?

Thanks in advance for your advice
 
Go with ISDN. Better quality IMO and you get CLI and other features not available to you in Analogue.

BTW trixbox is old news. Look at Elastix or AsteriskNOW for something more current.
 
I've recently setup a small PABX solution for my offices using a CentOS box with Freepbx. Using 2x analogue phones for both incoming and outgoing.

So far, I have had some issues whereby the system itself does not recognize when the inbound caller has hung up, which was extremely frustrating and the only way I have managed to solve was by jinxing the system into hanging up the calls if no sound is detected.

I honestly think for your situation, rather go with the system you intend to use and sign up for a good SIP provider. I'm currently searching for one myself and will let you know who I find to offer the best service.

If you could provide more info about your call centre, will you be doing more outbound than inbound calls? Have you got phones already will you be using Softphones?
 
m1k3072 said:
I've enabled CLI on my analogue lines, Telkom do offer it and it works with my current setup.
Click to expand...

Good to know, I'd still pick ISDN over Analogue.

I am not sure if a SIP provider is the way to go for small installations. ISDN does a good job for a number of our clients with those types of numbers. With things like CellSaver from Telkom you get very close to the savings you would from a VoIP provider.
 
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morkhans said:
Good to know, I'd still pick ISDN over Analogue.

I am not sure if a SIP provider is the way to go for small installations. ISDN does a good job for a number of our clients with those types of numbers. With things like CellSaver from Telkom you get very close to the savings you would from a VoIP provider.
Click to expand...

What would the costs be for ISDN though? Over and above the rental, would your call costs be the same as analogue with the advantage of having multiple channels?
 
m1k3072 said:
What would the costs be for ISDN though? Over and above the rental, would your call costs be the same as analogue with the advantage of having multiple channels?
Click to expand...

Rental IIRC is about double that of analogue (you get 2 channels per line), but check the Telkom site. Call costs are the same.
 
Hey guys

Thanks for the feedback.

I'm not too familiar with ISDN. You see, i want to use an 0800 toll free number for the call centre, therefore cannot use a SIP trunk. However, since it will be used almost 50:50 inbound:outbound, i am considering using a SIP trunk for cheaper outbound calls.

With, ISDN giving 2 channels, does that mean you get 2 telephone numbers with one line rental?
Also, can you utilize hunting on ISDN?

morkhans:
I'm using trixbox, because there is a wonderful plug-in for it, that integrates in with MS Dynamics CRM. Check it out here: http://www.wave-access.com/Public_En/trixbox.aspx
 
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m1k3072 said:
I've recently setup a small PABX solution for my offices using a CentOS box with Freepbx. Using 2x analogue phones for both incoming and outgoing.

So far, I have had some issues whereby the system itself does not recognize when the inbound caller has hung up, which was extremely frustrating and the only way I have managed to solve was by jinxing the system into hanging up the calls if no sound is detected.
Click to expand...

The fix for that is:
;Uncomment these lines if you have problems with the disconection of your analog lines
busydetect=yes
busycount=3

in your dahdi.conf file
 
I have decided I will definitely use ISDN.
Now there are a few options with regards to ISDN in terms of hardware.
I obviously require something that is approved with ICASA (so it plays well with Telkom ISDN and SA PSTN) and that is reliable for production use.
Anybody have any experience or suggestions?

I'm looking at the Quintum BRI gateway. There are also ISDN PCI cards available. What are the pro/cons with regards to external gateways vs PCI Cards?
I'm new to the whole VOIP revolution and would appreciate any feedback.

Thanks
 
rm501 said:
I have decided I will definitely use ISDN.
Now there are a few options with regards to ISDN in terms of hardware.
I obviously require something that is approved with ICASA (so it plays well with Telkom ISDN and SA PSTN) and that is reliable for production use.
Anybody have any experience or suggestions?

I'm looking at the Quintum BRI gateway. There are also ISDN PCI cards available. What are the pro/cons with regards to external gateways vs PCI Cards?
I'm new to the whole VOIP revolution and would appreciate any feedback.

Thanks
Click to expand...

I've always been dubious regarding gateways as I can't justify the cost vs. a Digium card and rolling your own with Asterisk, but that's just me.

If you are serious about Asterisk then I think you really need to consider looking for a reputable company who can talk to you about your requirements and implement a system for you.
 
i have had waaay to much crap with analogue cards with echo's, call volumes, and not detecting hung up calls, switched over to ISDN, and what a diffrence, muuuuuch better!! with no tweaking, it worked 100%
 
rm501 said:
Hey guys

Thanks for the feedback.

I'm not too familiar with ISDN. You see, i want to use an 0800 toll free number for the call centre, therefore cannot use a SIP trunk. However, since it will be used almost 50:50 inbound:outbound, i am considering using a SIP trunk for cheaper outbound calls.

With, ISDN giving 2 channels, does that mean you get 2 telephone numbers with one line rental?
Also, can you utilize hunting on ISDN?

morkhans:
I'm using trixbox, because there is a wonderful plug-in for it, that integrates in with MS Dynamics CRM. Check it out here: http://www.wave-access.com/Public_En/trixbox.aspx
Click to expand...

I think you could use an 0800 number with a SIP trunk. If your SIP trunk has a number associated with it, like 011/083/etc then you simply point the 0800 number you have to that number. You will just need to be aware of the charges applied to connect calls from telkom to that number i reckon.

With an ISDN setup, BRI, like you have - you could get a range of numbers associated with your circuit....so you could get 10 numbers, like 011 123 1000/1001/1002...1010. You could set aside some of those numbers for extensions if you liked, or each could be for a different queue in your call center. Your limitation is 2 simultaneous calls - which to me sounds like quite a serious limitation for a call center. 1 inbound 1 outbound max. Which means if 2 of your 8 agents are on the phone at the same time, the other 6 are not making any money?

Ive not actually seen this before, but im pretty sure you could add another BRI, get 4 channels, and have the number range terminate to both circuits. This also gives you redundancy in addition to some improved performance, but of course comes at a cost :)
 
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