[Techtalk] High speed access question
kath at kathweb.net
Wed Oct 3 13:05:26 EST 2001
Now when I go to say, Verio and ask for a channelized T3, do they go to the
ILEC and have the ILEC do the line from the school to the CO and then Verio
picks up from the CO to the Verio network (A bit like how the data CLECs and
the ILECs work?)?
Or would there have to be a dry run between the main access point for the
district and a Verio facility? I'm hoping its the first, as the ILEC CO is
literally next door to the school.
For a Tier1/2 provider, whats the best recommendation? I have experience
with Verio, they seem an okay bunch. AppliedTheory (Tier2-ish) does a lot
of K12s and colleges, and they go out to AT&T's net backbone. I'd rather go
right to Verio, but I know AppliedTheory does a lot of other services
(setting up routers and such). Does Verio do the same?
Now, on equipment. Does this mean I'll need a Crisco and CSU/DSU on both
ends of each line between the other schools and the main access point (the
HS)? Would a 2500 be enough on each end?
Bandwidth, looking at it, isn't a huge concern. File sharing apps are not
allowed, so it isn't a major risk. I think our biggest problem will be
serving AOL's webmail to people. =)
Back to equipment and diagramming. Would the network diagram be like?
Elem School Router --> Opposite router at HS --> Priv Network Switch -->
Firewalls --> Main Router to Provider
----- Original Message -----
From: "Raven, corporate courtesan" <raven at oneeyedcrow.net>
To: <techtalk at linuxchix.simegen.com>
Sent: Wednesday, October 03, 2001 3:00 AM
Subject: Re: [Techtalk] High speed access question
> Heya --
> Quoth Kath (Wed, Oct 03, 2001 at 12:34:18AM -0400):
> > - Would it be best to get every building a unique run to a Tier1/2
provider (decentralized)? I'm against it, I'd rather have all lines run to
one central district location and then out. It would be easier to firewall
and administrate than having 18 firewalls in 9 locations.
> It really depends on what you need as far as redundancy and
> uptime guarantees. Tier 1 providers are big, yes, but many of them will
> charge you more precisely because they are Tier 1. (And many
> marketroids will claim that their provider is Tier 1 without any
> conception of the actual meaning of the term. For those of you not in
> networking, a Tier I provider is one that doesn't have to buy transit
> from any other network.) It's worth investigating all the available
> competitors in your area.
> Are you looking at dual lines from the main office out to the
> Internet? If not, you'll be isolated if/when your line drops. And
> depending on who your regional LEC is and what sort of SLA (Service
> Level Agreement -- basically your contract with your provider), it could
> be days before you're up again. If this is not acceptable, negotiate a
> 2 or 4 hour turnaround time with your provider, or invest in redundant
> If possible, get your two main lines from different providers,
> or have them follow separate physical paths. That way, a failure in one
> (fiber cut, for example) is less likely to take out the other one as
> well. Redundancy doesn't do you much good if the circuits follow the
> same path and terminate in the same router on the far end.
> Will you be managing your own routers, or having the providers
> do it for you? If you are using multiple providers, you may have to do
> it yourself, since there's usually a "nobody touches this but us" clause
> in there for managed care.
> > - What kind of provisioning in terms of bandwidth should there be on the
line? A T1 connect (1.544 Mbps) from each school to the main location (the
HS)? What about from the HS to the internet?
> It honestly depends on how many folks you expect to be using the
> Net at any given time. If I were you, I would go for T-1's off a
> channelized T3, so that the actual run to your buildings is a T3, and
> you're just using 1/28th of it. The provisioning costs are usually not
> that different, and it makes upgrading later easier. Mention to
> whatever provider you select that you may want to upgrade these lines
> later -- they will recommend the easiest solutions for you from their
> product offerings.
> You may also want to consider Frame Relay, ATM, or some other
> technology that can be configured to let you burst traffic during
> periods of high usage, but get generally charged for a lower bandwidth
> connection. If you go with Frame Relay, make sure to ask what the CIR
> is. The CIR (committed information rate) is your guaranteed throughput.
> Many companies will try to sell you a circuit with a CIR of 0. Do not
> buy from them unless your budget is very low -- they're taking your
> money and guaranteeing you nothing.
> > When a "T1" line is installed, how hard is it to upgrade it to more
bandwidth? Does it require plant facility changes (putting down new fiber
or copper) or is it merely a change in the Criscos on both ends? (I'm not
saying going from fractional T1 to OC3+, but from T1 to T3 speeds).
> It totally depends on how they provision it in the first place.
> If you're part of a channelized T3, it's a thirty second config change
> on the routers. If you're not, you may be in for all the charges you
> originally encountered. Discuss this with your provider salespeople.
> > Would it perhaps be wiser to have the capacity for a large line (say, 45
Mbps), but negotiate with the provider so that the school would only use
what is paid for on a month to month basis? (This works out in the summer
when noone is there and therefore the internet is not used)
> Might be worth it -- compare prices for that vs. full T1's.
> Mention at first that you don't really know what your bandwidth usage is
> going to be like, and that you would like to be flexible about
> increasing it. And then once your lines are up and running, install
> MRTG on your handy Linux server to keep track of utilization. This is
> particularly useful in cases of billing disputes with a usage-based
> > - Also, what about multihoming? A few local schools here were knocked
offline following Sept 11th, as the West Street telecom hub was damaged, but
customers connected to 60 Hudson Street facilities were fine.
> True multihoming (to 2 different providers) may be overkill for
> you. It requires you to have your own AS (autonomous system) number,
> and your own IP block to route. Some providers won't accept a BGP
> announcement for anything smaller than a /24. Some won't accept
> anything smaller than a /19. If you're a basement multihomer, you may
> have problems getting your announcements heard. Your best bet may be to
> have 2 T3s to different routers in one provider. That way, you get your
> IP space from them, and you can just use a private AS number (analogous
> to using 10.0.0.0 for your machines -- it gets translated into the
> "real" AS number of your provider when it leaves their network.)
> Feel free to ask questions if any of this is unclear.
> "There shall be nine companions, to match the nine riders that
> are EVIL."
> -- Gandalf the Grey, in a humorously emphasized audio version
> of Tolkien's "Lord of the Rings"
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