At home and at work I use identical Macs (Dual 1.8 G5, OS X 10.4.4) with Limewire Pro 4.10.5. Work connection is SDSL, 1.1 Mb upload/download. Home connection is cable modem, 6 Mb down, 500 kbps up. Both copies of Limewire are configured identically with respect to search results & filters, etc. Bandwidth tests at work consistently report around 850 kbps up/down. At home, they report around 3.8 Mbps down, 350 kbps up.
My problem: at work, even tho much slower connection, I can average Limewire downloads around 90-100 kbps. At home, supposedly 5-6 times faster, I only average around 10-20 kbps. I've been reading in posts about ISPs sometimes rate-limiting P2P download speeds; even tho I've called my home provider and they deny doing so, I'm still suspicious.
Both home and work connections use static IP addresses. At work, there is a hardware firewall on the network that's been opened to Gnutella on port 6346. At home, I use a software firewall (NetBarrier), also opened to Gnutella on port 6346.
Given all the above info, is there anything I can do to improve download speeds at home? Besides switching ISPs, what can be done if they rate-limit P2P ?