[Asterisk-Users] My Sangoma Experience - Review

[Tom]

Thanks for the informative review Matt.  Please tell why you are using RBS 
T1 trunks instead of PRIs.  Is it the cost or availability issue from the 
ILEC/CLEC or is there some other advantage.  PRIs and RBS T1s are about the 
same price in my part of the world.

Tom

At 09:20 AM 4/7/2005, you wrote:
>My Sangoma Experience in Asterisk:                      2005-04-07
>
>Having pushed my Digium Asterisk systems to their capacity many times and
>figuring out the limits of the Digium hardware I decided it was time to test
>an Asterisk-compatible Sangoma Quad T1/E1 card(AFT-A104u) to see if they
>live up to their hype of being more efficient than the Digium
>variety(T405P). I had talked with someone from Sangoma before at Astricon,
>but it was rather informal, he didn't have any literature and I was rather
>swamped at the time as it was. Then I saw a posting on the asterisk-users
>list about the claims that the Sangoma card does echo-cancelation better as
>well as using far less interrupts than Digium hardware(a big bottleneck with
>busy Digium systems).
>
>I emailed Sangoma(they are located in Canada) for a quote and quickly
>received a phone call from them. They were very interested in getting my
>feedback on using their quad port T1/E1 card with Asterisk and they quoted
>me a discounted price of $1190 US for the card(They said retail was $1700 US
>[Digium quad-cards are $1495 retail but you can get them through resellers
>for a couple hundred less]). The Sangoma card comes with a 30-day money back
>guarantee and a 3 year warranty.
>
>When I received the card I noticed a couple things right away, it was a very
>professionally packaged item and it came with 4 T1 cables in the box as well
>as documentation and all of the other pretty things you expect in a retail
>package. The second thing I noticed is that the card was compatible with a
>2U form-factor(That's right, they crammed 4 T1/E1 ports together so it can
>fit in a 2U case vertically) This was achieved in-part because the ports are
>actually on a fixed daughter card, but it did bring up the thought that they
>could actually cram 6 ports on one of these cards :)
>
>Next I started to sort through the documentation and files on their FTP
>site. I noticed something I wish Digium cards had: User-upgradable firmware
>on the board(I have previously had to return an early version of the T410P
>Digium board to get a newer one with newer firmware on it).
>
>Let the installation begin. I started by downloading and installing Asterisk
>as usual(zaptel, libpri, asterisk[version 1.0.6]), then I downloaded and
>installed Wanpipe release 2.3.2 beta6. I could now see my card and went into
>the wancfg utility to configure my card. Here's when it stopped being a
>smooth experience. I tried installing it by the asterisk instructions found
>on the FTP site(which I found out later were out of date and incorrect) and
>eventually it all worked up until the final starting step. The drivers saw
>the card, but said nothing was connected to them which I thought was a
>strange problem since you don't have to have anything connected to a Digium
>card for Asterisk to fully startup. So I emailed tech support and walked
>through some reconfiguration steps and then after a few more emails back and
>forth it came out that they had a problem with D4/AMI signalling on a RBS
>T1(which they say they will have a fix for at some undefined time in the
>future). After switching the wanpipe config for the first span to B8ZS/ESF
>with a PRI T1 I was able to run ztcfg and asterisk. I placed some test calls
>and all went well, at least until I tried hooking up a live RBS(Robbed-bit,
>24 full channels not PRI) E&M Wink T1. It turns out that the guys at Sangoma
>have never had a customer that used E&M Wink start and accordingly they have
>never tested their cards with it, and of course it didn't work. So another
>email and call to Sangoma and they started working on a fix. Two days later
>they added a Wink for wink start T1s and sent me a new version of the
>software. I loaded it and it worked, but all audio and call detects stopped
>working if I tried to use more than 10 of the RBS T1 channels, so back to
>Sangoma for another new driver version. After a few days, and a few more
>driver versions, they came up with one that seemed to fix all of the
>problems I was having before so I did my simple stress test of picking up,
>hanging up and redirecting to meetme of about 52 Zap lines and all went
>well. Now on to the performance testing.
>
>For a performance test, I swapped out an identically configured machine that
>had a Digium T405P with my test machine and put it live in company
>inbound/outbound call center during off-hours to test(This server usually
>handles over 20,000 calls in/out a day with lots of recording going on
>across T1s, SIP phones and some IAX2 trunks). This server has two RBS T1s,
>one PRI T1 and one Channel Bank. I placed a test call out of the channel
>bank through the PRI and then started automated calls from the two RBS T1s
>to go into meetme conferences. The performance test ran great and it did
>prove that there is reduced CPU usage on a Sangoma board as compared to a
>Digium board. For a running time of about an hour the CPU usage was between
>30% and 50% lower with the Sangoma board on the identically configured
>machine. This was just doing some random calling maintaining 48
>conversations across all 4 T1s with calls lasting no longer than 1 minute.
>With these results I was very encouraged and decided to put the card into
>production.
>
>The production machine that I was replacing is one of our higher-volume
>Asterisk servers that routinely handles over 40,000 calls a day. To test
>compatibility and reliability of all of the hardware aside from the Sangoma
>card, I ran the server in production with a Digium card with no problems
>then the next day I put the Sangoma card back in and started it up. About 5
>minutes into production everything was going great, the load was very low
>for this machine and I was not noticing any channel_walk_lock warnings like
>I periodically see on Digium systems. Then at 10 minutes something happened
>and the card was not detecting Answers on any calls coming in or going out
>on either the PRIs or the RBS T1s. I had to reboot the machine to get it to
>start detecting Answers again. This was not good. I thought it was a random
>problem so we just started back up again, and then again after about 10
>minutes it happened again. I then put the Digium card back in quickly and
>rebooted and the server finished out the shift with no problems. The next
>day I took the server out of production and started running some more stress
>test on it. I couldn't get it to duplicate what had happened the day before
>even at higher volumes of calls than it was handling in the live
>envorionment. The next week we tried it again in production and the same
>thing happened except this time the machine froze. I was pretty sure that
>this was an issue with RBS T1s so I put the machine to the task of doing
>some PRI call routing between several Asterisk servers and it works just
>fine now PRI-only with no problems.
>
>Overall it isn't as easy to install a Sangoma Quad-T1/E1 card on an Asterisk
>system as it is to install a Digium card. But the support is very responsive
>to installation problems and I'm sure as more Asterisk users try Sangoma
>cards, the instructions will be updated more frequently and go more in-depth
>into the options offered by Sangoma cards. Throughout my tests I installed
>the Sangoma card and drivers several times on a few servers and by the end
>it was taking me about 10 minutes extra per install to get the Sangoma cards
>and their drivers ready for Asterisk usage.
>
>One minor confusing moment was realizing that Port 1 is on the bottom of the
>card unlike Digium where it is on the top. A minor annoyance with the
>Sangoma quad T1/E1 card is that you need to create a wanpipe config file for
>each span on the card and use another utility to specify the order in which
>they are loaded. One more item of note is that you need to wait several
>seconds after running 'wanrouter start' before you can start ztcfg or
>asterisk, if you do not, the spans may not come up properly.
>
>I am conflicted partially because when you buy a Digium card from Digium you
>are directly supporting the company that is the primary contributor to and
>maintainer of Asterisk(not to mention the lead-developer and creator of
>Asterisk is the CEO) and it is very important to support the core of this
>great application. It is important to note however that Sangoma has been
>contributing code to GPL Asterisk for a while now(they just recently started
>contributing directly as Sangoma) and seems to be doing more development
>with Asterisk as they get more Asterisk users as their customers. I do hope
>that Digium takes a look at what Sangoma was able to accomplish for roughly
>the same price point in a smaller form factor and will hopefully make some
>of the same advances in their cards in the future.
>
>I would not recommend a Sangoma card for a beginner user or those who depend
>on RBS T1s. Intermediate users and Asterisk Gurus who only use PRI T1s might
>want to try one of these cards if only to see if they can squeeze a few more
>channels of capacity out of their systems or get better echo cancellation
>and control of their card. There is no question that Sangoma has done a lot
>to improve on the zapata core hardware design and they will hopefully drive
>innovation in this growing market, competition is a good thing.
>
>Installation and test were done on Intel P4 systems running Slackware Linux
>10.1 with a custom 2.4.29 SMP kernel.
>
>MATT---