Please consider the following scenario: A new company wants to become a regional ISP. This company will purchase one or two large bandwidth circuits from a NSP of their choice. Then the new regional ISP will offer private line p2p Internet service to regional businesses. Basically, this is a small operation. Now here is the question. What choices does the regional ISP have when implementing routing and IP addressing? I assume the regional ISP will not implement BGP, since there will only be one maybe two upstream connections to a single NSP - initially. Furthermore, I assume the NSP would provide the regional ISP with a supernet - say a /20 or so. Then the regional ISP would allocate subnets of the supernet to their customer - say /24s. I also assume the regional ISP would not require an AS number since they are not implementing BGP. Basically, all traffic from the regional ISP and customers is default routed to the single upstream connection. Are these assumptions valid? Is this a good configuration? I realize multiple upstreams from different providers is optimal, however not plausdable in this case. Your constructive insight to the scenario is appreciated. Chas _____________________________________________________________________________________ Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com
Comments inline. On Tue, 12 Dec 2000, Charles Smith wrote:
Please consider the following scenario:
A new company wants to become a regional ISP. This company will purchase one or two large bandwidth circuits from a NSP of their choice.
Then the new regional ISP will offer private line p2p Internet service to regional businesses. Basically, this is a small operation.
Now here is the question. What choices does the regional ISP have when implementing routing and IP addressing? I assume the regional ISP will not implement BGP, since there will only be one maybe two upstream connections to a single NSP - initially.
You will have a marketing problem with this. Customers would like to see you connected to more than 1 nsp. Also, you sooner or later will get a customer that wants to multihome to you and another company. So, you'll really need to think about getting an as and running bgp I believe.
Furthermore, I assume the NSP would provide the regional ISP with a supernet - say a /20 or so. Then the regional ISP would allocate subnets of the supernet to their customer - say /24s.
Large subnets like this may be tough to get from an nsp. You may need to go directly to www.arin.net for this as well, since based on the above, you don't want your routing policy to be a reflection of 1 nsp.
I also assume the regional ISP would not require an AS number since they are not implementing BGP. Basically, all traffic from the regional ISP and customers is default routed to the single upstream connection.
See above, you could avoid circuit issues by multihoming to this 1 nsp, but what if they have a routing problem??
Are these assumptions valid? Is this a good configuration? I realize multiple upstreams from different providers is optimal, however not plausdable in this case.
Your constructive insight to the scenario is appreciated.
Chas _____________________________________________________________________________________ Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com
On Tue, Dec 12, 2000 at 08:59:11AM -0800, Brian W. wrote:
Now here is the question. What choices does the regional ISP have when implementing routing and IP addressing? I assume the regional ISP will not implement BGP, since there will only be one maybe two upstream connections to a single NSP - initially. You will have a marketing problem with this. Customers would like to see you connected to more than 1 nsp. Also, you sooner or later will get a customer that wants to multihome to you and another company. So, you'll really need to think about getting an as and running bgp I believe.
You're assuming a lot about his region. Plug any rural Oklahoma county in there, and his model is what's done.
True I hadn't considered setting your aim at customers who need a t1 or less and a /27, guess gaining experience in Ca. has its effects. Brian On Tue, 12 Dec 2000, Shawn McMahon wrote:
On Tue, Dec 12, 2000 at 08:59:11AM -0800, Brian W. wrote:
Now here is the question. What choices does the regional ISP have when implementing routing and IP addressing? I assume the regional ISP will not implement BGP, since there will only be one maybe two upstream connections to a single NSP - initially. You will have a marketing problem with this. Customers would like to see you connected to more than 1 nsp. Also, you sooner or later will get a customer that wants to multihome to you and another company. So, you'll really need to think about getting an as and running bgp I believe.
You're assuming a lot about his region.
Plug any rural Oklahoma county in there, and his model is what's done.
The assumption that your initial allocation of address space is going to be a /20 is probably incorrect. Allocation of address space is based on a slow start procedure outlined in RFC2050. What usually happens is that you request enough address space to be at 50% immediate utilization and 80% utilization within 3 months. To receive a contiguous /20 will probably require multiple IP requests and plenty of renumbering. =P t Charles Smith wrote:
Please consider the following scenario:
A new company wants to become a regional ISP. This company will purchase one or two large bandwidth circuits from a NSP of their choice.
Then the new regional ISP will offer private line p2p Internet service to regional businesses. Basically, this is a small operation.
Now here is the question. What choices does the regional ISP have when implementing routing and IP addressing? I assume the regional ISP will not implement BGP, since there will only be one maybe two upstream connections to a single NSP - initially.
Furthermore, I assume the NSP would provide the regional ISP with a supernet - say a /20 or so. Then the regional ISP would allocate subnets of the supernet to their customer - say /24s.
I also assume the regional ISP would not require an AS number since they are not implementing BGP. Basically, all traffic from the regional ISP and customers is default routed to the single upstream connection.
Are these assumptions valid? Is this a good configuration? I realize multiple upstreams from different providers is optimal, however not plausdable in this case.
Your constructive insight to the scenario is appreciated.
Chas _____________________________________________________________________________________ Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com
-- <!-- Todd Caine - tcaine@eli.net Electric Lightwave, Inc. 4400 NE 77th Avenue Vancouver, WA 98662 Direct Dial: (360) 816-4344 //-->
A new company wants to become a regional ISP. This company will purchase one or two large bandwidth circuits from a NSP of their choice.
Suboptimal, but as you note that the preferred alternatives are not feasible we'll press on.
Then the new regional ISP will offer private line p2p Internet service to regional businesses. Basically, this is a small operation.
Now here is the question. What choices does the regional ISP have when implementing routing and IP addressing? I assume the regional ISP will not implement BGP, since there will only be one maybe two upstream connections to a single NSP - initially.
Your choices are BGP or static. Using static routing becomes a poorer choice in the face of multiple upstream connections, but is technically possible. If you are dual-homing to get redundancy *and* you want to be able to get use out of both circuits, then you really, really, really want to be using BGP. There are options if using a static default, but you really want to be using BGP.
Furthermore, I assume the NSP would provide the regional ISP with a supernet - say a /20 or so. Then the regional ISP would allocate subnets of the supernet to their customer - say /24s.
You might find an NSP that would give you a /20; slow-start, as noted by a few others. They'll certainly allocate you some space, though, and give you more if you use up the first dose.
I also assume the regional ISP would not require an AS number since they are not implementing BGP. Basically, all traffic from the regional ISP and customers is default routed to the single upstream connection.
Correct. You only need an AS if you run BGP. If you are avoiding BGP because you don't want to go get an AS number from ARIN, you can ask your upstream provider if they either can support peering with you using a private AS number (64512-65535), or if they keep an AS number for singly-homes customers.
Are these assumptions valid? Is this a good configuration? I realize multiple upstreams from different providers is optimal, however not plausdable in this case.
Validity of assumptions is noted in-line. This is not a good configuration, but you go right on to say that the necessary building blocks for a good configuration are not available to you. Stephen
participants (5)
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Brian W. -
Charles Smith -
Shawn McMahon -
Stephen Stuart -
Todd Caine