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Tag: Multilink PPP

  • FreeBSD 9.2 on Jetway NF9H-525

    I wanted a new system to run as my router, so I set out to find a small system with at least three gigabit NICs. I settled on a Jetway NF9H-525 (also referenced as a NF9HQL-525), which is a mini-ITX board geared for networking applications with four onboard gigabit NICs and a dual core atom 1.8Ghz processor.  I also purchased an LGX MC500 case, two gigabytes of RAM, and pulled a drive out of a recently retired laptop. Bottom line: everything worked great and I would recommend it.

    The board has four onboard realtek gigabit NICs (RTL8111/8168B) which use the re driver. They’re not the beloved Intel em NICs, but they’ll do. Especially for the types of applications this board is likely to be used for – like my home networking. Same deal with the intel atom processor. The system can be a bit louder than I would have really liked, but the fan speed stepping does work so it’s only loud when it’s under a bit of load.

    I’m not going to bother including any build notes, mostly because I didn’t encounter any gotchas or oddities during the installation or configuration of the system. I read reports online that the NICs require a recent version of FreeBSD, but I didn’t have any issues with 9.2-RELEASE.

  • VDSL + MLPPP + FreeBSD + Xen = Awesome

    I signed up for the new 25Mbps VDSL services that are becoming available through TekSavvy, now that Bell has to provide speed matching profiles to other providers instead of just the staid old 5Mbps profiles they used to offer.

    The techs were done by the time I got home, but one of them was nice enough to install a proper POTS splitter for me, which was nice. According to the person present at the time, he said something to the effect of “I don’t know if I’m supposed to do this, but I think Mike will appreciate it”.

    My router is a Xen virtual machine, running a hardware virtualized FreeBSD instance, with three NICs passed to it using PCI passthrough. I use packet filter for the firewall and traffic shaping, and MPD5 to handle the actual MLPPP tunnel.

    Once I got home I connected the router to the cellpipe modem, and right away the PPPoE came up. Subsequent testing showed that I actually got slightly better performance by configuring mpd to bring up two full tunnels on the single line and then bond them together than I did by having mpd bring up just a single MLPPP enabled tunnel.

    Speedtest Result

    I had been concerned that the virtual machine wouldn’t be up to the task, but it appears that isn’t much of a concern. I haven’t done any testing with new MTU/MRU values yet, so there’s still a possibility of improving performance slightly from here, but I’m already getting pretty much what was promised, so I don’t know how much further it could go.

  • FreeBSD and Multilink PPP

    I’ve been running Multilink PPP with FreeBSD for several years now. Multilink PPP (sometimes called MLPPP) is a subset of the PPP protocol that allows you to bond multiple PPP tunnels and treat them as one much larger tunnel. Several DSL providers (particularly TekSavvy in Canada) support Multilink PPP on their DSL networks, allowing users to bond multiple DSL lines into one large pipe.

    The technical details of Multilink PPP are pretty simple, though it can be configured in either a packet splitting or round robin fashion. When configured for packet splitting, a router that is about to transmit a packet down an MLPPP link will first split the packet in half, then add a 6KB MLPPP header (really just a sequence number) to each half of the packet, and send the half-packets down each link. On the other end of the MLPPP link, the receiving router will take the two halves (identified by the matching MLPPP headers) and reconstitute the original packet. In round robin mode the MLPPP header is added to the whole packet (meaning the MTU of the link is 6KB smaller or else packet fragmentation will occur) and sent out the links in a round robin fashion.

    In FreeBSD it’s easy to setup just about any Multilink PPP configuration you want. I’ve run it with three DSL lines (total usable throughput: 15 megabits). Presently I’m running over one DSL line but with two PPPoE tunnels first multiplexed at the DSL frame level and then bonded at the PPP level. The purpose of this is to circumvent Bell Canada’s throttling, which they apply to both their own residential customers and to their third-party wholesale partners, like TekSavvy.

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