Internet Exchange - AMS-IX, NL-ix,...

Summary

An Internet Exchange (IX) is a physical infrastructure that enables entities (autonomous systems) to exchange Internet traffic between their networks by means of mutual peering agreements, which generally allow traffic to be exchanged without cost.

Peering on an Internet Exchange can improve network performance (shorter paths), improve reliability (multiple paths to destinations) and reduce cost.

An Internet Exchange connection starts at 100 Euro per month for 100 Mbit/s on the NL-ix Internet Exchange and goes up to 2.500 Euro per month for 10 Gbit/s on the AMS-IX Internet Exchange. Open Peering is reseller of both, and can provide IX ports as part of a turn-key solution.

Description

General Setup

Nowadays an Internet Exchange is generally based on ethernet technology, and provides each member with a switch port into a shared ethernet VLAN. All IX members connect their BGP4 router on that port and have direct zero-hop ethernet connectivity to all other members, which enables them to set up peering sessions and exchange traffic.

No traffic exchange without peering agreement

Once connected, members can technically reach each other. But before actual BGP peering sessions can be configured and mutual traffic can be exchanged, parties will first have to negotiate a peering agreement on a bilateral (one-on-one) basis which each party they want to peer with.

Public versus private peering

Peering with an other party can be done over a dedicated point-to-point network cable between between the BGP4 routers of each party. This is called private peering (sometimes also called private interconnect in analogy to peering of telephone networks). Alternatively it can be done over the public infrastructure of an Internet Exchange. Then it is called Public peering.

Why is private peering with many parties not efficient?

Doing private peering with a substantial amount of other parties soon runs into a scalability problem: for peering with 'n' parties, each party would need 'n' cables to connect to each other party, giving in total 'n*n' cables.

With for example 150 parties this would mean 150*150=22.500 cables. This would drive the total interconnect infrastructure costs up very high. Especially if the parties are not all located in the same datacenter, but spread over multiple datacenters, long distance network cable costs become very high.

Private peering can still be efficient, if a substantially large part of your traffic is exchanged with a small amount of parties. If the absolute traffic level to a specific party is high enough and interconnect costs are low (for example when you are in the same datacenter), then private peering can still be very useful.

Why is public peering on an Internet Exchange efficient?

On an Internet Exchange, each party basically needs only one port (to the Internet Exchange), giving in total 'n' local (in-datacenter) cables for all parties. The Internet Exchange takes care of carrying traffic between parties on different datacenters and does this much more efficiently because of scale advantages. This renders the actual physical location of each member and the distance between them practically irrelevant.

With the concentration of many peers on on single port, this model has considerably less scalability issues and member interconnect infrastructure costs. And even if individual peers represent only a (very) small amount of your traffic, public peering is still useful if at least the total traffic volume handled over the Internet Exchange via peering is substantial enough.

Advantages of peering on an Internet Exchange

Peering on an Internet Exchange has several obvious advantages:

• An Internet Exchange connection gives you direct high speed access to a large amount of potential peers at relatively low absolute, per-peer and eventually per Mbit/s traffic costs;
• The Internet Exchange port is not free, but actual payload peering traffic over the port is, in most peering agreements, free of charge;
• A direct peering with an other party guarantees a very short and fast connection to that party, faster then otherwise possible;
• Peering on an Internet Exchange provides resilience as peers can be reached both via regular global transit and via the Internet Exchange. These paths back each other up;
• Peering on an Internet Exchange can have a marketing value if your customers expect you to be connected to an Internet Exchange or have a higher esteem for your company if you are connected to an Internet Exchange.

Limitations of peering on an Internet Exchange

Despite the advantages of peering on an Internet Exchange, realistically there are also some limitations on peering that need to be taken into account to prevent disappointments:

• With just an Internet Exchange port you still cannot exchange any traffic. You can only exchange actual payload traffic with parties with whom you have a peering agreement;
• Negotiating peering with a lot of potential peers is a lot of work, generally about one year in turn-around time, and one month in man hours;
• Larger parties generally tend to have strict peering policies, e.g. demand a minimum mutual traffic level, equal in:out ratio of traffic, peering at multiple geographically dispersed locations (e.g. countries or continents), etc.
• As a general rule of thumb, the larger and more interesting parties get, the more strict their peering policy becomes;
• So even after a lot of effort to negotiate peering, after the first year you might very well still have peering with only for example 60% of all Internet Exchange members, and those being relatively more the smaller peers covering maybe 50% of you local traffic.

Which Internet Exchanges exist in Holland?

Which Internet Exchange to connect to?

Basically the worth of an Internet Exchange connection is determined by these basic factors:

• How many parties are connected to the Internet Exchange?
• How much traffic do those parties exchange with each other;
• What percentages of the amount of routes in the global routing table (+/- 220.000 in total) are represented at the Internet Exchange;
• How much of your traffic has a source or destination that lies within those parties? This is often regionally defined: generally a very substantial part of your traffic (60%+) goes to a small amount of parties and a small amount of routes that origin in your own region or country (for example Holland);
• How many of those connected parties are potential peers for you: with how many of them could you realistically agree upon peering?

So you would normally select a large Internet Exchange in terms of membercount, traffic volume and amount of routes, while taking into account that you are mainly looking for peers that represent a substantial volume of your traffic (region), and with whom you can realistically expect to reach a peering agreement.

Is connecting to multiple Internet Exchanges useful?

Connecting to multiple Internet Exchange is useful for redundancy reasons, and because different exchanges have a memberlist that does not 100% overlap, giving you better coverage.

Top-10 Internet Exchanges in the world by #members

* This data is per January 2, 2007

Largest Exchanges in the world by traffic volume

Al list of the top-41 largest Internet Exchanges in the world by traffic volume (only IX's larger than 1 Gbit/s of traffic) can be found on the Wikipedia page.

Documentation on Internet Exchanges

For more details about Internet Exchanges, please have a look at Wikipedia.

Pricing

NL-ix

* 10 Gbit/s ports are not available on all datacenters.

AMS-IX

Conditions

Exchange access can be delivered by Open Peering

Open Peering is both NL-ix and AMS-IX reseller and can provide connections to both exchanges, with full IX membership.

NL-ix Datacenters

NL-ix can provide ports on these datacenters.

Pricing for 10 Gbit/s NL-ix peering ports is based on delivery on the euNetworks, GlobalSwitch, Nikhef, SARA, Telecity1, Telecity2, Telecity3 (Redbus) datacenters. On other datacenters custom pricing for 10 Gbit/s applies.

AMS-IX Datacenters

AMS-IX can provide ports on the GlobalSwitch, Nikhef, SARA and Telecity2 datacenters in Amsterdam.

Open Peering can extend AMS-IX connections to all of these datacenters. The costs for extention are datacenter-specific.

Port

• 100 Mbit/s ports are available on RJ45/UTP connector only;
• 1 Gbit/s ports are offered on multimode fiber (SX/850nm) by default, but also available on singlemode fiber (LX/1310 nm) at an additional initial fee of € 500,-;
• 10 Gbit/s ports are available on singlemode fiber (LR/1310nm) exclusively.

Does not include patchcable

The demarcation point of the service is the port on the NL-ix or AMS-IX switch on the datacenter. After an order is placed with Open Peering, in the order confirmation a NL-ix port or AMS-IX ID will be assigned. With that port ID the customer can order the patchcable from its equipment to the NL-ix or AMS-IX port with the datacenter directly.