Hosted PBX
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@JaredBusch said:
SIP calls take 100k. So when Bob calls Sally, you are eating 200k of bandwidth on your pipe. With 50 extensions you can add this up quite quickly.
It's important to note that 100Kb/s is just over the theoretical maximum of g.711 calls. We use that number to be an easy to use large number that cannot be exceeded under any condition by a call. It's a safety number for engineers to make sure that calls never get choked by underestimation. It's important to use, but also important to understand.
In reality the maximum is like 99Kb/s, but that makes the math harder for no reason. It's close enough to 100Kb/s and having a tiny buffer for other misses is good. But there are a number of things to consider when using the number...
- If there is silence suppression, moments of silence (which are more common than you think) will drop to almost zero.
- If there is compression on the line, this might get reduced depending on the compression.
- If you don't use g.711, you can drop this number dramatically (at a cost to call quality.) There are several protocols for this, some reduce the size only a little, some a lot. There are about half a dozen popular protocols. Not all carriers are going to support those, so your mileage will vary. It is common for one or two additional to be supported. If you are using a hosted PBX, you generally get a lot or all of the major ones. If you go in house, your SIP trunk provider likely only offers two in most cases (with one having a charge associated with it.)
- If you are using the full 100Kb/s size, you can opt for your internal calls to use g.722 for HD audio using the same envelope, which is quite nice. But almost no one does this because... it's a phone, who cares.
- If you add video to the call, which SIP supports, 100Kb/s is not even remotely enough
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@scottalanmiller said:
I've worked with a lot of PRIs that are far worse.
You post this all the time. I'm curious - considering that you've worked with thousands if not hundreds of thousands of PRI circuits, what percentage of them were horrible? 1%? .1? less?
I've worked only with 10's of PRIs and while I've had the occasional issue, and most of the time they are resolved fairly quickly.
I've with with SIP through vontage and a few other home based options, and just recently put SIP in my office. All of these options are noticeably poorer voice quality than the PRIs I've experienced.
Poorer enough to go back? Nah - of course not. Which moves me to @wrx7m question - when will SIP be as good as old school PRI - I would think the answer is never. Consider the medium through which you are delivering most SIP trunks. The internet a free-for-all network with best effort routing.
To me the question is - is it good enough? So I'd say the answer is yes. -
@Dashrender said:
@scottalanmiller said:
I've worked with a lot of PRIs that are far worse.
You post this all the time. I'm curious - considering that you've worked with thousands if not hundreds of thousands of PRI circuits, what percentage of them were horrible? 1%? .1? less?
I've not worked with that many, those are huge numbers.
But of what I've worked with, 1% is laughable. Probably more like 40%. It's enough that I consider it the fundamental risk to voice communications. So large that even if PRI is just 1% of the market it dwarfs the cumulative risk of VoIP of the other 99%.
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In this case, lumping PRI and other legacy circuits. "Non-VoIP"
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@Dashrender said:
I've with with SIP through vontage and a few other home based options, and just recently put SIP in my office. All of these options are noticeably poorer voice quality than the PRIs I've experienced.
Remember you can really only compare those services to POTS to be fair at all. When I went from POTS to Vonage, quality went up, even in 2003 or whenever we put that in. And reliability went through the roof.
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@Dashrender said:
Poorer enough to go back? Nah - of course not. Which moves me to @wrx7m question - when will SIP be as good as old school PRI - I would think the answer is never. Consider the medium through which you are delivering most SIP trunks. The internet a free-for-all network with best effort routing.
I don't agree and believe you are comparing false things.
SIP is better than PRI in every way. Apples to apples there are zero downsides to SIP. It is more efficient, sounds better, costs less, is more flexible.
If you are talking public shared lines to dedicated lines, which is not PRI vs SIP, then dedicated will sound better and public will be more reliable. Just nature. True for either protocol. For any protocol. The different there between SIP and PRI is that one degrades and the other fails. Which, again, makes SIP superior.
What you are comparing is apples to oranges to feel that SIP has any deficit. It simply does not. If you look at how they work, it is impossible for PRI to compete or have a place in the modern world. Nearly all PRI today is delivered over SIP for exactly that reason - because PRI is so poor that SIP can deliver it. If you think PRI is good, by extension you think SIP is fantastic.
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@Dashrender said:
Consider the medium through which you are delivering most SIP trunks.
This is the important point and cannot be missed... it is the medium you are hearing (or think you are) that doesn't sound as good, not SIP. SIP itself isn't even the audio carrier. On Vonage, they do not use g.711 in order to save money, so you are also hearing their compression. That's now a VoIP or SIP problem, it's a choice of the system in question.
It's very important to isolate the factors and know what is being compared and what is causing the things you feel are inferior. I can have SIP calls that are terrible - but where PRI would not be available. Do you call "total failure" a "really bad call" or do they get a pass by not being able to do it?
It's the Linux and Windows problem - Linux is tremendously easier than Windows in most cases. So much so, that people just assume that they can do things on Linux (and often can) that are impossible on Windows. They feel that "hard" is somehow "harder" than "impossible." This, of course, makes no sense. Nothing is harder than impossible.
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@JaredBusch said:
@anonymous said:
We are looking at getting a new onsite PBX, but I have started to think maybe it makes more since to use a Hosted PBX...
What are the Pros and Cons? Anyone have a vendor they like for this?
Assuming that you are only going hosted with your own PBX not something you buy from someplace else.
The technical pros and cons mean go hosted unless your bandwidth can handle the trunk calls but not the in house calls. This is really the biggest concern. SIP calls take 100k. So when Bob calls Sally, you are eating 200k of bandwidth on your pipe. With 50 extensions you can add this up quite quickly.
Because hosted gets your some generally very good reliability. If there wasn't you would not see that host surviving for very long in today's market.
You lose easy redundancy (can't just replicate to another (VM host) with hosted most of the time but with such high reliability, that is a serious mitigation of the risk.
Keeping it on site, you end up with easy redundancy options, but the reliability will suffer. On the other hand you do lower the monthly cost (no hosting) and only add a very minor burden to your VM infrastructure.
What if I run it onsite, with backup server hosted? Seems like the best of both worlds?
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I know that the newer companies like Cox and Comcast are delivering PRI over SIP. Which is why I had little concern over moving to a QOS link provided by Cox for my SIP services.
Again looking at my only other personal experience with SIP being Vontage (oh and I suppose my home service which is undoubtedly SIP converted to analog in my house) Vontage over the internet was not as good as most POTS service I've had in the past. You say your service was better on SIP, I'm guessing that the infrastructure for your POTS lines was just old and crappy so of course you're going to have more issues than my younger system out here in sticks
I do agree that SIP is the we should all be moving.
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@anonymous said:
What if I run it onsite, with backup server hosted? Seems like the best of both worlds?
If by hosted, you mean you buy some space on the internet that you can replicate your settings to, sure that sounds good. But I wouldn't pick a hosted provider - that would be much more expensive.
You do all the work for both places. You setup failover paths for your calls to the other location you setup for your SIP trunks.
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@Dashrender said:
I know that the newer companies like Cox and Comcast are delivering PRI over SIP. Which is why I had little concern over moving to a QOS link provided by Cox for my SIP services.
That's the one way I would never consider SIP. SIP from an ISP is better than a PRI, but is still so awful as to simply be outside of my willingness to consider. Other than lowering cost and increased call quality and flexibility, all of the problems of the legacy world are carried along with it. Dedicated lines for incredibly call quality stability are fine if the budget can justify it, but I know of no case where any service tied to an ISP is okay be it email, DNS, registrar, phones, web hosting, etc.
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@scottalanmiller said:
@Dashrender said:
I know that the newer companies like Cox and Comcast are delivering PRI over SIP. Which is why I had little concern over moving to a QOS link provided by Cox for my SIP services.
That's the one way I would never consider SIP. SIP from an ISP is better than a PRI, but is still so awful as to simply be outside of my willingness to consider. Other than lowering cost and increased call quality and flexibility, all of the problems of the legacy world are carried along with it. Dedicated lines for incredibly call quality stability are fine if the budget can justify it, but I know of no case where any service tied to an ISP is okay be it email, DNS, registrar, phones, web hosting, etc.
As you know, others might not, this was not my choice - while I do personally feel more comfortable (mainly because of my legacy comfort in PRIs) with a provider to my site whole responsible party, I do certainly understand your points.
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@Dashrender said:
@anonymous said:
What if I run it onsite, with backup server hosted? Seems like the best of both worlds?
If by hosted, you mean you buy some space on the internet that you can replicate your settings to, sure that sounds good. But I wouldn't pick a hosted provider - that would be much more expensive.
You do all the work for both places. You setup failover paths for your calls to the other location you setup for your SIP trunks.
Right, setting up and managing the replication will eat at your savings for switching to SIP. Also, in order to even get the offsite PBX useful, you have to be able to answer the calls. If you are failing over to it in the first place, you are going to be having problems and getting all the internal phones switched to register to the different IP is not a trivial task.
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I am thinking about a couple of ways to provide easy fail-over in the case of a data center outage.
Each SIP phone supports up to three accounts. Would I able to setup one account to one location and another account to another location?
This seems like to me it would work just fine, but I wonder if I am missing something? I would create different sub accounts for each location, then if we had a failure, I would just have to point my DID (Just one in my case) to the other sub account. What I am missing?
Also, it seems like you can have 2 SIP servers per account? Would this be another way to go?
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@anonymous said:
Each SIP phone supports up to three accounts. Would I able to setup one account to one location and another account to another location?
Yup, that is actually a common strategy.
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@scottalanmiller said:
@anonymous said:
Each SIP phone supports up to three accounts. Would I able to setup one account to one location and another account to another location?
Yup, that is actually a common strategy.
But, I feel it is a flawed strategy. I am not at home at the moment. I'll try to get back to this later.
tl;dr of my response will be use a fail over destination at the SIP provider and have backups ready to restore elsewhere.
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@JaredBusch said:
@scottalanmiller said:
@anonymous said:
Each SIP phone supports up to three accounts. Would I able to setup one account to one location and another account to another location?
Yup, that is actually a common strategy.
But, I feel it is a flawed strategy. I am not at home at the moment. I'll try to get back to this later.
tl;dr of my response will be use a fail over destination at the SIP provider and have backups ready to restore elsewhere.
Using other strategies is often better, I agree. But it does work as imagined. But is odd and complex with a dependency on end point configuration in multiple places.
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@scottalanmiller @JaredBusch Would using 1 account with 2 SIP servers be a better way to go?
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@scottalanmiller said:
@Dashrender said:
@scottalanmiller said:
I've worked with a lot of PRIs that are far worse.
You post this all the time. I'm curious - considering that you've worked with thousands if not hundreds of thousands of PRI circuits, what percentage of them were horrible? 1%? .1? less?
I've not worked with that many, those are huge numbers.
But of what I've worked with, 1% is laughable. Probably more like 40%. It's enough that I consider it the fundamental risk to voice communications. So large that even if PRI is just 1% of the market it dwarfs the cumulative risk of VoIP of the other 99%.
WTF?
You know I worked for some large telecoms. I've put in PRIs, BRIs, T1/T3, OC-x, even worked on a few 5ESS switches in the old days. A PRI is nothing more than an extension of the central office to your own PBX, running on the worlds most reliable equipment. Of ALL the telecom technology out there, PRI is the MOST reliable service out there for voice. The circuit, not the ancillary equipment around it. PBXes fail, usually due to lazy telcom admins. I've lost all internet connections to the world over multiple pipes in a single location but the PRI was still running just fine. Like most things, 90% of "failures" are self inflicted, bad configs, bad equipment. I've seen loops need some changing and fixing, but never outright fail out the blue without any reason.
There's a reason Ma Bell setup the network the way she did. If I have to trust anyone, it's gonna be AT&T's legacy network.
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@PSX_Defector said:
Of ALL the telecom technology out there, PRI is the MOST reliable service out there for voice.
T1, which is a dependency of PRI, is simply not that dependable. I have no idea where anyone gets the impression that T1s are reliable, but they just aren't. Whether it is because of aging technology or because of contractual protection that keeps providers from needing to fix download lines or because PRI is too complex for providers to provision (I'm lookin at you, Windstream) the result is that PRI has a dependency that isn't reliable and hasn't been reliable compared to cheaper options for decades.
