I have a friend with a Vodafone supplied and branded HG556a dsl router.
Every 5-20 minutes it will drop the internet connection.

As far as I can tell it doesn't drop the dsl line connection, as the status page says it has been up for days.
I am connected by wifi with full signal strength and not moving around.

As an example of the problem:
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=2ms TTL=64
Reply from 192.168.1.1: bytes=32 time=4ms TTL=64
Reply from 192.168.1.1: bytes=32 time=2ms TTL=64
Reply from 192.168.1.1: bytes=32 time=11ms TTL=64
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Reply from 192.168.1.1: bytes=32 time=42ms TTL=64
Request timed out.
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
Reply from 192.168.1.1: bytes=32 time=113ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64

I had a continuous ping going to the router and when it went Requesd Timed Out, other programs with connections up also died, for example an ssh connection died rather than timed out so i'm thinking the router must be somehow closing the connections.

I have done a factory reset and its now doing it less, but still happening.

I have a theory it is the wifi radio on the router restarting, but no evidence.

Router firmware V100R001C12B028


Anyone had anything similar?