Sipura provide firmware updates for their SPA-3000 analogue VoIP adapter. They include a Windows program to upgrade the firmware, which is of no use to those of us who don't use Windows.

Fortunately, it's very easy to upgrade the firmware via tftp, http or https. All you need is access to a tftp, http or https server.

To upgrade the firmware without using a Windows PC:

Note: I've read reports that echo is worse with v3.x firmware than with v2.x. I didn't run v2.x for very long - I had problems with incoming caller ID with v2.0.13g, which were fixed in v3.1.10d, and I didn't try to solve my echo problems until after I upgraded, so I can't say whether v2.x was any better. I don't use the SPA-3000 any more; I first replaced it with an Open 812L, but now I have an IP04 runnning Asterisk.