Fax over T38 works and works reliably. We have many in the field at customer sites. The trick is configuring all the devices correctly; SIP trunking provider, SBC, Asterisk, and ATA. There are actually MFP devices that claim they have native support for SIP/T38 but I've never tried getting one of these to work.
That being said, virtualFax (fax to email and email to fax) is a much nicer solution. I don't like faxing over T38 but it's there and it works if you need it. With respect to handsets; Aastra are starting to fall behind since they were purchased by Mitel. Used to be our "go-to" phones, robust and stable, easy to provision, but now falling behind. Cisco SIP phones (SPA series) were originally SIPura phones (thus the SPA in the model name), then purchased by Linksys, then purchased by Cisco. The Linksys SPA942 was a great phone in it's day but it's starting to show it's age. Cisco stopped releasing firmware updates for it years ago and we've been phasing them out of service ever since. We trialed Grandstream at one customer and ended up replacing them for free due to the very poor quality and haven't touched them since. I would assume they have improved in the last 6 years. The Polycom VVX series are arguably the best quality phones but they are not the cheapest. If you look at the larger hosted voice providers, most of them use Polycom. The difference in the cost of the handset spread over a 5 year contract is less than $1/month. The nice thing about the Polycom VVX series is that they are compatible with a variety of systems, including Microsoft Lync. That means the investment is protected if you want to change platforms at a later date. Digium also has handsets now. I've never tested them. All of the above being said; in my opinion, the days of the "home rolled" Asterisk PBX deployment are over. You can buy a fully featured, manufacturer supported, configured and deployed PBX from a major vendor for less than the cost of a server with an FXO card running FreeXXX based on Asterisk. If you are a hobbyist and enjoy that sort of thing then great. But if you just want a feature rich, stable, hassle free PBX at a good price; Asterisk is probably not the best choice. Regards, John
