[dllthomas]

"Settlement-free peering assumes that bandwidth usage is roughly symmetric: when it's not symmetric, the side sending more bandwidth has to pay."

I've never understood why this is - especially in a case like this, where the sending side is sending because (the customers of) the receiving side explicitly asked for it.

[exelius]

Because the cost of a packet is borne by the receiver while the sender is the one monetizing it.

The assumption is that if you're sending traffic to a customer, you are being paid for that activity through subscription fees, ads, donations, etc. That packet costs the receiver some minuscule amount to process. Even though it was requested by the ultimate receiver, the ultimate sender is only sending the packet because they make money from doing so. The middlemen only pass on the packet because their costs are covered and they make a small amount of profit. This setup also ensures that if the packets aren't being monetized in some way (i.e. if it's a DDoS) that there's a financial incentive to stop them.

[njharman]

> you are being paid for that activity through subscription fees, ads, donations, etc.

Last time I checked ISPs where heavily monetizing packet receiving to the tune of 5-10x what netflix monetizes from me. For typically slow, shitty service bundled with cable TV or phone I do not want.

[dllthomas]

... and it's probably pure coincidence that Netflix is in direct competition with 1/3 of that bundle, too.

[wmf]

Because the cost of a packet is borne by the receiver...

That's true for hot-potato routing, but CDNs generally use cold-potato routing.

As for monetization, both Netflix and Comcast are getting paid by their respective customers.

[exelius]

It's no less true for cold-potato routing; the source is just closer to the endpoint. And CDNs doing cold-potato routing happily pay for their transit because the service THEY make money off of is providing CDN services to their customers, who theoretically make money off the content they pay the CDNs to distribute.

What it comes down to is Comcast has no incentive to ensure its routes to various Internet transit providers are GOOD if they're not monetizing them. Why should Comcast be treated differently than any other transit provider and not allowed to monetize its transit services? Netflix wasn't paying Comcast, so Comcast had no responsibility to help Netflix make its own service better when there were other ways Netflix could have alleviated the bandwidth situation (e.g. buy transit through another company).

[nitrogen]

Comcast has no incentive to ensure its routes to various Internet transit providers are GOOD if they're not monetizing them.

Customers pay Comcast with money to establish those links. If that's not "monetizing", what on earth is?

[namecast]

The original L3 article actually touches on this, sort of, by mentioning markets where ISP port congestion is not an issue (i.e. the UK) due to competition between ISPs.

Comcast will get paid by their customers as long as the routes they pass traffic through are 'good enough'. They have a (near) monopoly on the last mile in many markets, so 'good enough' can mean both 'barely working' and 'better than any other option you've got' at the same time.

So, you're right, but so is the parent: Comcast has no financial incentive to provide any more than just enough bandwidth to keep you from calling the support line to complain or cancelling your contract in frustration.

Where's the rest of customer revenue going, if not towards network upgrades? Well, let's just say the Comcast Center (http://archrecord.construction.com/projects/bts/archives/off...) ain't paying for itself...

[dllthomas]

As others have said, Comcast is also being monetarily rewarded here. I think the best argument lies along "the sender is in the best position to take measures to reduce traffic (traded off against their goals)."

[exelius]

They are rewarded for providing access; not for passing individual packets. There's a difference.

[dllthomas]

How precisely are they providing access if they do not pass individual packets?

Edited to add: It's certainly true they are not rewarded for the marginal packet, but then neither is Netflix (given their subscription based model).

[zero_intp]

Level-3 is actually going around to their peers and trying to create systems to measure the bit-miles traversed on traffic sent to other tier-1 peers; the carriers will then pay for out-of-sync ratios