choosing a backbone provider avi freedman vp, engineering abovenet communications
TRANSCRIPT
Choosing a Backbone Provider
Avi Freedman
VP, Engineering
AboveNet Communications
What to look for
• Performance– How fast are they when things aren’t broken?
• Reliability– How much of the time are they broken?– How badly do they break?
• Friendliness– Will they speak BGP and work other issues?– Clueful 24x7 Support
• Price
The Platonic Network
• Always up; zero packet loss to any destination on the ‘net; instant response to all technical questions, debugging issues, route filter changes; $400-600/mbit on a usage basis.
• No such provider exists.
What to Shoot for
• Always up, modulo 5-minute failovers a max of once/month;
• Fastest class of connectivity;
• 15-minute support on urgent problems, via phone if needed, and 2-4 hour turnaround on all solvabe issues;
• $1000/mo/t1; $3000/mo for base frac T3; down to $450/mbit in large quantity.
Performance
• There are two sides to backbone performance -– Internal backbone performance– Peering
• Right now, independent verification of performance is hard. Keynote and MIDS suck.
• Soon, there will be other measures.
Performance (ctd)
• The ideal performance philosophy -– Backbone: Run an uncongested network
everywhere, aiming for no more than 50% use of the backbone links in normal circumstances, to allow for bursting and allow flow to expands.
– Peering: Peer with everyone, everywhere, even at one location, globally. Honor their MEDs, and cold-potato traffic over your less congested network. Put in private interconnects to any provider you do > a few mbits/sec with.
Performance (ctd)• Many backbones have diseased peering policies,
usually for political reasons, sometimes out of cluelessness.
• So ask for their peering policy. The policy itself is as instructive as the list of peers, but you want to see that also (or get a looking-glass view).
• When asking for peers, ask for who is via private interconnect.
Performance (ctd)
• Remember, Sprint, UUNET, CW are not the net. Nor are any 9 providers. Just connecting to the bigger providers can give you OK connectivity, but wide uncongested peering down into the 50% of the ‘net that is the smaller networks is key.
Robustness
• Get into the internal architecture of the network and customer-attach points with sales engineers.
• There should be multiple fiber vendors, multiple routers at every point, and they should support cheap or free same-provider multi-homing (ISDN, Frame, SMDS backup). Ideally, different router vendors as well, though that’s hard/more rare.
Robustness (ctd)
• Performance is harder to get answers on, but existing customers of a given backbone can give you a good measure of robustness/downtime.
• The inet-access mailing list (send a message with the body containing the word subscribe to [email protected]) is a good place to ask, as is around ISPF, ISPCON, etc...
Robustness (ctd)
• The SLA (Service Level Agreement) is your tool to get credits based on downtime, and even, if things are really bad, the ability to leave a term contract.
Friendliness
• You want IP space, as reasonable (you WILL have to justify all space nowadays).
• You want them to speak BGP with you for free; help you set up BGP; and make route filter modifications within a few hours.
• In an emergency, you want them to get someone senior on the phone.
Friendliness (ctd)
• You want them to limit ICMP to 128k/sec or so to you from their network, to stop the effect of smurf attacks.
• You need to be aware of whether the provider uses the RBL (maps.vix.com/rbl) and if you don’t want to be affected by it, they need to be willing to help you route around it.
Price
• $1000/mo for a T1 on a term price for a good provider is a good rate (plus local loop).
• $3000/mo for a 3mb/sec frac T3.
• $450/mb at t3 speeds, via T3 or ethernet.
So, Who?
• Many regional providers
• AboveNet (disclaimer, I work for them)
• UUNET
• Globalcenter
Regional vs. National Provider
• A regional provider can combine connectivity to people with wide global peering like AboveNet, and backup paths (not too many) to enhance redundancy, and access to other regional ISPs via peering and customer relationships.
• Usually easier to find friendliness, and being able to go beat on someone in person can be handy.
Regional vs. National (ctd)
• Also, usually can negotiate cheap or free ISDN, Frame, or SMDS backup via redundant path.
• Downside: Concerns about business stability over time.
