Digium (Asterisk) versus ShoreTel - Purchasing Decision

btaplin used Ask the Experts™
I am trying to gather some information that will assist me in making a purchase decision, Digium or ShoreTel.

Approx 50 users, 3 Sites, 3 Appliances (Larger System at HQ, 2 Smaller Systems at Branches). Plan to Use SIP over Fiber with a few backup Analog Lines, Some Blackberry/Softphone Integration, Unified Communications with Dashboards, 1 Main Company and 2 Smaller Companies In-House which will require separate Call Distribution/Auto-Attendants.

The pricing that has been presented by the two companies bidding for my business is about the same. Both systems will provide failover to alternate locations.

Everything with Digium is self-contained within the appliances (Voice Mail, Administration, RAID, etc). ShoreTel requires a seperate server (which has been factored into the price comparison). Not sure if this is a good thing or just something else to maintain.

Digium Appliance (for HQ) has Redundant Fans and Power Supplies, ShoreTel doesn't.

It seems as though the Digium System has more features included. ShoreTel has them too but you have to pay to unlock.

The management of both systems seems very straight forward (although I have to maintain the additional server with ShoreTel).

I have also read that ShoreTel isn't the best choice for SIP (not sure how true this is or not). I do know we've been quoted a SIP 'Connector' called a SIPerator with the ShoreTel system.

Adding phones/users will be more expensive log-term, should I choose ShoreTel.

From what I can tell ShoreTel is very reliable (the main reason they are still in the running), I'm not certain about the Digium System.

Can anyone provide any additional information (or can help substantiate what I have stated) to assist with my purchase decision?

I am only looking at Digium and ShoreTel and will not be considering any other manufacturer/vendor. I have already narrowed the choices down to these last two providers.

Thank you very much.
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Asterisk integrates smoothly with all that is SIP. As matter of fact, the last SIPit event was held by Digium:


I have mainly deployed pure Asterisk solutions, and I can tell you, if Digium doesn't provide the necessary support, you will find lots of information from the community. They operate differently (Asterisk and Switchvox), but Asterisk performance in scenarios similar to yours has been truly outstanding.

The flexibility in terms of features is also very nice. Propietary systems (delt mostly with Cisco) tend to be very hard to scale due to licensing and proprietary protocols implementation.

How important is a the feature richness of the system?
How important is redundancy and high availability?
How important is the access from the users to the configuration to maintain basic features?
Your initial analysis is accurate.

ShoreTel will scale fine and is considered a leader in business telephone systems, but it is true they treat SIP as an optional element instead of building their product around SIP as Digium/Asterisk has.  Ongoing costs will be higher with ShoreTel but they do provide a more traditional support orgainization with authorized distributors and a strong manufacturer role.  Because ShoreTel is more hardware-based than the open source Asterisk some decisions will be dictated to you by the manufacturer.

If you like the opportunity to customize or add capabilities, Asterisk is far more open and flexible.  If you are looking to put it it and leave it alone, ShoreTel might be a bit better fit.

Re the third question above, ShoreTel has an excellent desktop client that provides easy access to features and allows the users to manage the portion of the configuration that affects their profile and telephone.  However, it is a "fat client" and requires updating as the OS changes.

I have had several clients remove an Asterisk for another more traditional telephone system (usually due to support issues) but I have never had a client using a ShoreTel remove it for an Asterisk.  However, Asterisk based systems have captured a significant market share and are no longer.

ShoreTel does offer many slick enhancements, but you will pay more for them if you want them.  Also, they indicated to me during a factory visit that they far prefer to sell their collaboration add-on features rather than integrate with others (such as Microsoft Lync).

In general, you would be making a good choice with either one of the systems, but you will pay more over time for ShoreTel if costs are a significant factor for you.  If traditional telephony support is critical, then ShoreTel may well be worth it.  If you like more control over your system, the Asterisk is the better choice.
Shoretel is a closed platform, you pay for everything, Asterisk is essentially open, what you're being charged for with *, is someone's packaged it and has a 'server solution'.

Asterisk is free for G711, G729 codec requires additional licensing.  Since most providers use G729 over G711 (~40kb/s per call rather than ~80kb/s), you can utilize your bandwidth better.  

If you're considering Asterisk, or a commercialized version, a lot of people look to TrixBox (Fonality), as a decent unified communications solution.  Any way you slice it, NAT traversal is potentially your biggest issue with *.

All things considered, * is a better platform if you're interested in being able to do sip debugs (asterisk -r, set sip debug on), and want to be able to integrate things like dialer scripting, roll your own voicemail, and a lot of other great features, but it's more of a swiss army knife for SIP.

At 50 extensions (and ostensibly 50 concurrent calls), you can do it all off one decently beefy box and skip the remote sites, just having them reach out and touch it over your network (whether it be IPSEC VPN, MPLS or frame relay private VRF).

Were I to size your application, I'd put one box with SAS raid 1 @ 146GB (something like an HP DL360G6/7) with 12GB of ram.  Your biggest scaling issue is going to be with call setup, actual streams take almost no processing.

I've sucessfully run asterisk on a RackSpace VM running 500 concurrent outbound calls per VM for trunk testing.  I've seen Fonality's Trixbox (commercialized * implementation) for 120 users on a call center floor (at Fonality's office).  I currently have customers who generate 120 outbound calls every 30 seconds off a single box not quite as beefy as the I just described.

ShoreTel will put you squarely in the realm of commercial (very closed) telecom equipment providers, where *, and even a commercialized version, will give you a lot more granular control and debug capability.  It really depends on what your interest level in understanding SIP is.

For that matter, you could roll your own box and *, and have a really nice pure SIP PBX.

There's another question that springs up, how are you going to connect your PBX to the outside world?  SIP/IAX on the inside is fine, but you're going to have to terminate outbound calls to someone, and get inbound DID termination (possibly from the same company, possibly not).  Are you planning to use CAS, PRI, or straight SIP?  There are tradeoffs for every scenario.

CAS/PRI - vendor has very little visibility into call quality problems without expensive proprietary equipment, you can use at *at least* 23 channels on a single t1 (probably overkill for 50 stations).

Typical residential over-subscription on trunking is 10:1, typical commercial is more like 4:1, so for every 4 stations, you need to have at least 1 trunk channel for inbound/outbound calls.  

With SIP, you're basically limited by your upstream bandwidth, which on G711 is going to get you around 19 calls for a maxed out T1 (most providers configure as 20, but the 20th might not go).

It's also very likely that your provider is running SIP all the way out to an IAD on your premises, to convert that to PRI or CAS on the IAD, will end up causing you headaches with call quality and DSP performance.  

With SIP, that transition is clean, the calls come all the way in and hit the PBX directly, as long as there's no packet loss or excessive jitter, everything is smooth, clear and clean, no matter which G7xx variant you use.

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Thank you for your input.

We're in the same boat.  Which system did you go with?
Digium also has a hosted solution for $35/user/month.  All features included.  2,000 US domestic local long distance includeded per user that is shared by the account. So 50 users...

Your Plan Would Include
Monthly Cost: $1,750.00*

50 user extensions with Digium's Total UC feature set
50 DID numbers with E911 service
100,000 local/domestic long distance minutes
1 Automated Attendant**
1 Call Queue**
MeetMe Conference Center

* Estimated monthly recurring charge for budgetary purposes only. Actual monthly bill may include taxes and/or fees for additional services. For a formal quote, please use the form above.
** Additional Automated Attendants and Call Queues can be added for a one time setup fee. There are no additional monthly fees associated with these feature additions.


You can also look at Switchvox by Digium, which is based on the Asterisk but in a "closed appliance" approach that removes much of the hassles related to self supporting an open-source platform.
Since it is a premises-based solution it avoids the hosted approach if that does not match your needs.
And Switchvox will cost less than ShoreTel.

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