VPNs, Third-party websites, and bandwidth

[Rumor_Watkins]

Here's the setup:

My ISP doesn't shell out for ESPN3 (the internet video ESPN service)
I have (completely legitimate) access to an academic VPN that has ESPN3 access
I can connect to my academic VPN, get the academic IP address, and watch ESPN3

Does my connection tunnel through the academic servers? if I'm A, school is B, and ESPN is C, does the video feed go through A-->B-->C-->B-->A ? I suspect it does, and my concern is that I'm not going to get as high a data transfer rate since all the data is traveling through an intermediary.

So, what's the straight dope!

[spinky]

Yup, that's the way it works. In particular, your computer sends a request A->B->C and ESPN sends a video stream in response, C->B->A. It's possible your transfer rates can suffer from this, but it's also possible that the new hops in the network don't have much impact.

Interesting datapoint: I noticed that Hulu puts a local TV station's "bug" in the corner of TV shows I watch, and I figured that must be based on my IP. So I tried watching some shows while connected to my VPN, which is in St Louis. Sure enough, there was a different station's bug in the corner, and when I looked up that station's web site, it was a local St Louis station.

[si_blakely]

And don't forget, the VPN is encrypted, so all the video data is being transformed at each end of the VPN link. This is a major limiting factor on your connection, particularly on your end. The VPN concentrator at the far end could well be a dedicated piece of fast hardware, but at your end, the CPU is decrypting data and then decoding video, putting a fair load on your computer and restricting throughput.

Si

[Rumor_Watkins]

Originally Posted by si_blakely

And don't forget, the VPN is encrypted, so all the video data is being transformed at each end of the VPN link. This is a major limiting factor on your connection, particularly on your end. The VPN concentrator at the far end could well be a dedicated piece of fast hardware, but at your end, the CPU is decrypting data and then decoding video, putting a fair load on your computer and restricting throughput.

Si

any chance that this depends on the VPN software you're using? my VPN has instructions to set up via Cisco VPN and via Windows' built in VPN. It specifically states that the Windows VPN is not preferred as the data sent that way is not completely encrypted...

[si_blakely]

Originally Posted by Rumor_Watkins

any chance that this depends on the VPN software you're using? my VPN has instructions to set up via Cisco VPN and via Windows' built in VPN. It specifically states that the Windows VPN is not preferred as the data sent that way is not completely encrypted...

PPTP is not great, as compared with IPSEC (as used by Cisco). However, it is still encrypted.

Si