[107903] in North American Network Operators' Group
RE: Today's Point-2Point WAN Options
daemon@ATHENA.MIT.EDU (Chris Kleban)
Wed Sep 17 14:50:47 2008
From: Chris Kleban <Chris.Kleban@citrix.com>
To: Paul Wall <pauldotwall@gmail.com>
Date: Wed, 17 Sep 2008 11:48:52 -0700
In-Reply-To: <620fd17c0809151933k61a41be7t77e21c892584e9cd@mail.gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
See my comments inline below.
The one question I have coming out of this is:
If I want an economical sound solution that offers me high bandwidth and th=
e ability to ensure end-to-end QoS, what is my best choice?
So for it seems like a wavelength service meets those needs, with the negat=
ives being that I need to deal with possible long outage times and manage t=
hings like fiber path redundancy myself.
MPLS vpn services came in a close 2nd, but the price points I am seeing are=
outrageous.
>>Chris Kleban <Chris.Kleban@citrix.com> wrote:
>> Hello Nanog,
>>
>> I'm currently looking into what are the options for enabling inter-datac=
enter communication.
>>
>> Our current solution is to use ipsec/gre tunnels traversing over the Int=
ernet. The specific needs the new solution must meet are:
>>
>> - The ability to run end-to-end QOS.
>
>What are you trying to accomplish?
>
>Do you need to be able to pass DiffServ/DSCP tagging between sites?
I'll be pushing different types of traffic (voice, video, http, nfs, etc) a=
cross the wan and want my different traffic classes queued appropriately fr=
om end to end. What I don't want is for there to be any layer 1,2,or3 hop t=
hat doesn't trust/pass/act on my dscp markings.
>> - WaveLength Services (oc3-10gig): This service seems to be cheaper then=
traditional leased lines when comparing similar bandwidth. However, availa=
bility is limited to on-net buildings. This solution meets my needs.
>Not a bad idea, but often overlooked when purchasing unprotected long-haul=
waves is that you can be down for days or weeks on end, depending on the s=
everity of a given fiber cut. And protected waves cost significantly more =
because the carrier is provisioning twice the capacity -- sometimes in a co=
nfiguration not as redundant as advertised. This is not for the faint of h=
eart, and best left to ISPs who are buying from multiple vendors/cable syst=
ems and put in the effort to engineer suitable diversity. As an end-user, =
a switched service might afford you more economical route protection.
There seems to be some more work required in managing things like fiber pat=
h redundancy yourself versus letting a carrier do it for you.
>> - Dedicated bandwidth
>> - Support 1gbps transfer rates
>> - Enable communication between 3 locations
>Okay.
>> The options I have looked into so far are:
>>
>> - Layer 2 Ethernet (Virtual Private Line): This service seems to be offe=
red by a lot of ISPs using various networking >techniques. The price point =
is attractive however packets are forwarded only at best effort across the =
ISP's network which means >the quality of the service will directly reflect=
the ISP's network performance.
>How is this a problem? Is that concern that you never want an interface w=
hich is (physically, to routing protocols, ...) "up" but >latent and droppi=
ng packets like whoa, from an application or monitoring/management prospect=
ive?
Jitter/loss can affect ef type traffic (voice) severely and I am trying to =
avoid this.
>You raise a valid point about oversubscription. At the same time, this is=
often overhyped by marketing people, and dependent on how ghetto your pseu=
dowire provider is and whether or not they know how to capacity-plan.
>> - Traditional Leased Line (dsX/ocX): This service seems to be more expen=
sive then wavelength services however meets my needs.
>Quite. And it limits your router options significantly while driving up c=
apex costs. Just say no!
>> - MPLS based VPN solutions: Seems to be a good point to multipoint techn=
ology with QOS offerings. However, the price seems to be around the same as=
wavelength services for the amount of bandwidth we require. If the number =
of data centers we were looking to connect was larger then this option woul=
d be more attractive. This solution meets my needs.
>(Assuming you're talking about l3vpn, as l2 can be grouped into your first=
example...)
>It would probably help if you'd explain the "QOS" feature set of the offer=
ings you're looking at.
>This is a highly technically complex deployment; even at the largest telec=
oms, you can count on one hand the number of staff expert in its implementa=
tion and troubleshooting. It's also the most limiting in terms of specific=
routing protocols and prefix counts supported, the type of traffic you can=
pass, etc. The only benefit I can see to a l3vpn is in the enterprise wit=
h a lot of branch offices, where it simplifies end-site configurations and =
hub/spoke topology. Connecting your three datacenters, this is obviously n=
ot an issue. These are often the most expensive solutions too, given that =
their target customers have deep pockets.
>> Based on my needs and what my options are I am leaning towards point to =
point wavelength services connecting my 3 locations in a loop like fashion.
>>
>>
>> Are there any other options I should consider?
>None come to mind.
>> Are my descriptions of the today's possible solutions inaccurate?
>More or less, though it would help if you'd explain more what you're tryin=
g to get out of the "QOS".
Best Of Luck, and Drive Slow,
Paul Wall
