Category: Service Providers

During my last Building IPv6 Service Provider Core webinar I got a lot of questions about IPv6 over PPPoE (obviously we’re close to widespread IPv6 implementation; I never got PPPoE questions before). I wanted to test various scenarios in my IPv6 lab and thus enabled PPPoE on an Ethernet link between CE and PE routers.

This time I wanted to test multiple configurations in parallel ... no problem thanks versatile PPPoE implementation in Cisco.

The attendees of my Building IPv6 Service Provider Core webinar get several sets of complete router configurations for a six router lab that emulates a typical Service Provider network with a residential customer and an enterprise BGP customer. The configurations can be used on any hardware (real or otherwise) supporting recent Cisco IOS software, allowing you to test and modify the design scenarios discussed in the webinar.

Following my “Transition to IPv6” articles, Jessica Scarpati from SearchTelecom.com wrote a series of articles covering the telecom transition plans and the problems they’re experiencing with the vendors and content providers.

In the second article of the series, “Deploying IPv6? Demand responsiveness from vendors, content providers”, she’s quoting John Jason Brzozowski from Comcast, John Curran from ARIN, Matt Sewell from Global Crossing and myself. My key message: vote with your money and take your business elsewhere if the vendors don’t get their act together.

As expected, my P2P traffic is bad for the network post generated lots of comments; from earning me another wonderful title (shill for Internet monopolies) that I’ll proudly add to my previous awards to numerous technical comments and even a link to a very creative use of BitTorrent to solve software distribution problems (thanks again, @packetlife).

Most of the commentators missed the main point of my post and somehow assumed that since I don’t wholeheartedly embrace P2P traffic I want to ban it from the Internet. Far from it, what I was trying to get across was a very simple message:

I’m positive you all know that. I also hope that you’re making sure it’s not hogging your enterprise network. Service Providers are not so fortunate – some Internet users claim using unlimited amounts of P2P traffic is their birthright. I don’t really care what kind of content these users transfer, they are consuming enormous amounts of network resources due to a combination of P2P client behavior (which is clearly “optimized” to grab as much as possible) and the default TCP/QoS interaction.

One of the biggest hurdles Internet Service Providers will face in the near future is access to legacy IPv4 content once we run out of globally routable IPv4 addresses. Although it’s easy to offer your content over IPv6 (assuming you have a properly designed network using load balancers from a company that understands the need for IPv6 in Data Center), a lot of the “long tail” content will remain reachable only over IPv4.

A few days ago my friend Greg (also known as @etherealmind) wrote an interesting tweet (probably prompted by the change in AT&T data plans):

If a data cap doesn't affect 97% of users, why bother implementing it at all? Surely the 3% can be that significant?

A few of us immediately responded that the 3% could represent 80 (my guess) to 97% (@icemarkom) of the traffic. As I’m tracking my home Internet connection with MRTG for over a year, I was also able to get some hard facts (although the sample size is admittedly very small). We’re pretty heavy internet users (no limits on what my teenage kids are doing and I’m mostly working from home), but the average yearly utilization of my 20 Mbps pipe is only 180 Kbps or less than 1% of its capacity (still, over a year, that’s almost 700 GB of data or 350 months of AT&T’s DataPro plan).

IS-IS has “forever” (at least since RFC 1195) supported multiple layer-3 protocols, but always with a nasty side-effect: if a link in your network did not support one of them, you could get hard-to-diagnose black holes.

The problem is illustrated in the left-hand column of the following diagram. Due to a single IS-IS topology, the shortest path between A and B is the direct link, and since IPv6 is not enabled on that link (click on the diagram to get an enlarged version where you'll be able to see the link colors), A and B cannot exchange IPv6 traffic even though there’s an alternate path between them.

Last November I was delighted to read the announcement describing how a module in CRS-1 was going to support CGN, NAT444, NAT64 and DS-Lite. It looked like a major vendor has finally decided it’s time to solve the IPv4-to-IPv6 transition problem.

However, I was not able to find anything beyond a few fancy videos, a white paper and a brochure. Can anyone shed more light on CGv6? Have you seen it running outside of PowerPoint? When can an IPv6-embracing Service Provider expect to see it on an ASR 1000?

I while ago I wrote two articles for SearchTelecom that deal with traffic management in Service Provider networks and Deep Packet Inspection (DPI). The first article analyses whether you need dedicated boxes doing the traffic management in your network; the second one whether you really need DPI to manage the traffic.