Is there a way to speed up download from RHN ?

Hi everybody,

I'm becoming mad with the slow downloads I have to do from RHN.

When I'm doing a "yum update", or ever worse, downloading an ISO, I download at 6K/s.

For RHEL 6.1 BETA, for example, I get an eta of ... 7 days.

As the download link for ISOs are valid a limited period, I have to start again the download again and again...

Very time consuming, in fact.

I already tried by night, but I couldn't get better speeds.

Is there any way to speed up the downloads, or to switch (ever manually) to another mirror ?

Thanks in advance for your help :-)