I had a similar problem on a home phone. My actual download is about 850kb/s . Vonage (my phone supplier) talked me through the problem so do talk to your VOIP supplier. I am thinking of getting a ISP with more than the current 1 Mb. Say about 8. You never actually get the width claimed. Can you get a higher speed package? I found a setting in the phone account that gave an improved performance but I am far from an expert.