Let me begin by saying that I am a big fan of Digium in general. All of their products that I have used thus far in several IP telephony / VoIP installations have worked tremendously well.
Background: Doug and I recently integrated a Digium AA50 phone system appliance with Polycom IP telephones for a small business with moderate call volume (approximately 50-60 outgoing long-distance calls daily and many more incoming calls). The system is attached to 3 analog Embarq telephone lines (with rollover from one main number) via the AA50’s FXO ports and a 2-call limit VoIP trunk with CallCentric.
The phone network is powered, VLAN’d and QoS’d by a Dell PowerConnect 3548P that is capable of delivering Power-over-Ethernet (PoE) to all 48 ports. Users of the system can plug their laptops into the provided and automatically VLAN’d Ethernet pass-thru on both the SoundPoint IP601 and IP331 phones; this is a really nice feature of the SoundPoint models we use and allows you to only have one jack for two devices while still keeping voice and data on separate VLANs. The 3548P switch is really slick in that it came with multiple VoIP provider VLANs programmed in already (based on MAC address); any devices from those manufacturers are automatically placed into the voice VLAN on the switch. Oddly enough, the Dell switch did NOT have an entry for Polycom, though it did come with presets for Cisco, Aastra, Avaya and a handful of others.
The AA50 phone switch, Dell 3548P and associated firewall (a Linksys WRT54GL running OpenWRT for VPN, QoS and VLAN capability) and DSL modem are all backed up by an APC UPS SUA750XL that, at current load, gives the customer about 90 minutes of runtime during a power outage.
We utilize the licensed g729.a codec internally and over our VoIP trunks with CallCentric to minimize bandwidth consumption.
The AA50 appliance is used with (3) Polycom SoundPoint IP601 with sidecars for receptionists, (1) Polycom SoundPoint IP6000 conference phone and (10) Polycom SoundPoint IP331 phones. Having worked with interfacing Avaya, Aastra and Polycom phones to Asterisk in the past (trixbox, Asterisk Business Edition and the like), I will continue to pick Polycom hands-down for interoperability with Asterisk, with Aastra as my second choice. Avaya makes amazing systems, but they add so much proprietary stuff on top of SIP that I have found that the phones are more trouble to work with than Polycom or Aastra, which adhere much more closely to established standards.
Review: On the AA50, usability would have received 5 stars, except that some advanced setup functions still require getting under the hood and modifying config files by hand. One setting that should be built into the GUI is a limit for number of simultaneous calls on a given trunk; to do so requires editing users.conf by hand. I do not believe that it is possible to add more than one VoIP trunk provider via the web GUI at this time either, but perhaps I missed something.
Another thing that hurt usability is the location of stored config files on the system. Because this system uses a CF card, files are not located in the places you would expect to find them on an Asterisk system. Once you figure out that the CF card is mounted in /var/lib/asterisk/sounds/, you are good to go. It is important to note that some normal Asterisk functionality (such as CDR) does not appear to be functional because of CF card limitations.
I would have liked to have seen in the web GUI and documentation a better reference to the “advanced options” switch that allows you to do such things as modify config files using the web GUI. This option is hidden in the menu until you explicitly enable advanced options, which is annoying.
Pricing is ok on the AA50 if you are not able or willing to put together your own whitebox solution. If you know what you are doing, hindsight tells me that I would now recommend going the whitebox route; you can build two systems and have one for a spare for the retail price that the AA50 sells at.
Unfortunately, the AA50 does not support sending syslog events to a remote syslog server. SNMP is not available that I am aware of and enabling the “full logging” in logger.conf is futile; the full log gets wiped when the AA50 reboots because the log is stored in volatile RAM and not on the CF card; there is no way to redirect the log that I am aware of. Currently, I have a cron process that logs into the AA50 every few minutes and grabs the latest log information.
***ISSUES: As of the date of this writing (02 Nov 2009), we have two major issues which Digium has confirmed are issues for multiple customers: Issue 1) The system spontaneously reboots, whether or not calls are currently in progress. Fortunately, the system reboots very quickly (~20-30 seconds) and it is almost unnoticeable if you have low call volume. It takes phones a few seconds to re-register with the server though and so phones are out of service for upwards of a minute when a spontaneous reboot happens. Apparently this spontaneous reboot situation is attributed to a memory leak, but Digium is not aware of the exact problem and does not have a resolution as of yet. I am told by Digium that they previously had a memory leak issue and remedied it quickly, but are having a harder time tracking it down this time.
Issue 2) The CF memory card will spontaneously change to read-only mode while the phone system is in operation. As the “hard drive” and only permanent storage in the system, this is a huge issue because when the CF card is mounted read-only, you cannot leave or delete voicemails. The system will function as if nothing is wrong, but then fail to actually write or delete voicemail. At that time, you have to umount the CF card and remount it using the command line or reboot using the web interface. Another related symptom: If the CF card goes to read-only mode while someone is leaving a voicemail, that voicemail will be corrupted and you will not be able to delete or use the space occupied by the voicemail until you delete the file manually using the command line.
Another really quirky issue with the AA50 is that the WAN and LAN ports both share the same MAC address and there is no way that we could figure out to override this permanently. This makes things really interesting when you plug the WAN and LAN ports into the same VLAN’d switch; trust me, it is not pretty. We ended up routing all traffic via the LAN port and do not use the WAN port for anything. This required a little creativity and I would be happy to share our config if anyone is interested.
We purchased a Gold support contract with Digium because it provides advanced hardware replacement in the event of failure and it took several weeks to actually receive the support certificate for some unknown reason. Digium even told me at one point that they did not even sell support for the AA50 any more, even though they still showed this offering for sale on their own web site! Not receiving the certificate might have prevented us from getting support from Digium, but the tech I ran across was kind enough to give us a pass and address our issue even though he could not verify that I had purchased support.
Overall, support from Digium has been better than what you would receive from a typical tech company, but it has not been stellar. Techs have followed up with me while I have an open ticket, but it takes them quite a while to do so and this does not seem to be standard practice, but more just getting a good tech (i.e. it might not be policy).
When I call Digium support, I always get someone right away, but I am usually told that I will be put into a callback queue after my contact and issue details have been taken. It seems that Digium has little resources dedicated to supporting the AA50 appliance and not many Digium techs I have spoken with seem as comfortable with this unit as they are with the Switchvox product line. As a matter of fact, it often seems that I know just about as much about this unit as Digium does and that is not comforting. Typically, I receive a callback within 1 hour, but this can be an eternity if you have a terribly broken system and can not take or make calls. For the high cost of the support agreements, better service should be afforded to the customer.
I will wrap up by saying that our reseller, VoIP Supply (Arthur Miller in particular) have been stellar. Arthur was tremendously helpful during pre-sales, ushered and expedited our order after-hours when we needed equipment ASAP (and called at the 11th hour) and he even helped to escalate these issues with Digium. Arthur has done a tremendous job and I can wholeheartedly recommend VoIP Supply to others. If you would like to contact Arthur for purchases, please let me know and I will send you a private message with his contact details.
I will update with another review when we have a resolution to these issues.
Filed under: Asterisk / Trixbox / Telephony, Business, Linux, SIP, Technology, VoIP / Telephone | 12 Comments »