Best ISP for VoIP .SIP & RTP traffic?

I have tried a few ISPs but none seem to prioritise VoIP RTP/SIP traffic. Some are good (F2S), some are appalling (Eclipse) even on business packages.

Changing ISPs every 2 months costs a fortune.

Is there any ISP out there that actually recognises that VoIP traffic is real time/high priority and should be dealt with differently?

- David

Is there any ISP out there that actually recognises that VoIP traffic is real time/high priority and should be dealt with differently?

You'd have thought any ISP offering a VOIP bolt-on service (Zen, BT, Plusnet, etc.) would do so, but somehow I doubt it (except, possibly Zen - as they're about the best you can get anyway).

VOIP works perfectly from an Entanet connection (due, primarily, to their ALT anti-loss tool, which drops speeds a little to preserve pings and keep packet loss at a minimum).
I can use VOIP at any time (24/7) regardless of the central loadings, and can't even tell the call is not a normal voice call (no delay whatsoever).

My four previous ISPs (Ace/Mistral, Eclipse, Metronet, Plusnet) have all been appalling for VOIP (although ACE is now using Entanet - but probably not for much longer, and wasn't too bad with Mistral, until they started getting throttled).

One thing that is worth noting, and will add to any ISP "issues", is if you're using a "softphone", and/or a USB VOIP phone plugged into your PC - There's plenty of stuff going on (including various processes, and bl--dy Norton) that can cause delays and drop-outs.
Using a hardware VOIP phone, or VTA (both of which plug straight into your router - or connect via wireless), are the way to go if you're concerned about performance.
Also, stay clear of Skype, as it seems to have delays that make it obvious you're a cheapskate and are using VOIP (not a problem with personal calls, but trying to do business over a dodgy "VOIP" product seems unprofessional).