Local network delays was good before
Terrible network delays on BT Homehub 3 router
Running an iMac (OSX) 10.10.5 I started to get horrendous network delays both when browsing and also when performing peer to peer network file transfers. My system had always been fine up until now.
I run a BT Homehub 3 router which has always had an extremely limited range, but other than that it had been fine.
When pinging other machines on the network I got network timeouts or massive delays.
Checking the setup of the router (Advanced settings / Wireless configuration) I noticed I had specified a channel for the wireless comms. I must have messed with that a while ago and forgotten about it. It's likely that a neighbour is using the same channel as me and that can cause conflicts and packet retries - the likely cause of my problem.
Selecting Automatic (Smart Wireless) solved the problem immediately. This setting means the router checks the channel it wants to use to ensure there is no local interference before permanently selecting it.