There is more to IXPs than meets the eye

IXP 3

CCR October 2013, acm delivery

2. IXP 101

2.2 basic operations and services

a clear and open policy for others to join [24]

flexible interpretation of the types of network infrastructures that can be considered as IXPs

networks (also called participants) that want to exchange traffic at a given IXP are generally expected to comply with the following basic requirements ...

each incur a one-time cost for establishing a circuit from their premises to the IXP, a monthly charge for using a chosen IXP port (higher port speeds are more expensive)

IXPs typically do not interfere with the bilateral relationships that exists between the IXPs.
IXP

clearly satisfy the main reason for why they exist in the first place --- keeping local traffic local
- IXP’s public peering service is typically offered at a cost below the cost incurred by exchanging that same traffic using more conventional means — the participants’ upstream providers
- IXP participants often also experience improved network performance and QoS due to reduced delay
most operational IXPs also have offerings for “private peering”
- private network interconnects (PNIs)
- a well-provisioned dedicated link … handle relatively stable but generally high-volume bi-directional traffic
other services offerings … increasing number of today’s IXPs include service level agreements (SLAs) for participants

2.3 business and operational modesl

largest and most vibrant and innovative IXPs reside in Europe and are managed non-profit IXPs (e.g., DE-CIX, AMS-IX, LINX)

DE-CIX: owned by eco association (largest non-profit association for the Internet industry); views its participant networks as customers (or participants), not as members or shareholders; the IXP’s management team reports to the eco association and not to its own customers
European IXP model: due to their openness and explicitly stated mission to work for “the good of the Internet”, much is known and publicly available about these managed non-profit IXPs … topologies … expansion plans … traffic statistics … service offerings and pricing lists
North American IXP marketplace: dominated by for-profit IXPs whose first and foremost interest (indeed, mandate) is to generate profits for their shareholders
Asia/Pacific region: … both

3.1 know your IXP data sources

since the number of connected networks and traffic volumes are often used as metrics for success ... even these managed by non-profit IXPs are generally very protective of their customers' inherently more sensitive data related to their operational model and prevailing business relationships and publish neither the IXP peering matrix nor its corresponding traffic matrix

3.2 surprised by the obvious

the observation in [55] … a peering matrix with a fill rate of some 60-70% (50K+ active peerings)

there are easily more than 200k public peering links in today's Internet, ... the ration of AS links of customer-provider type to peer-peer type is not, as has been commonly assumed, about 3:1 but more like 1:2 or 1:3

The concept of operating a router server at an IXP and offering its free use to the IXP’s members originated within the European IXP model and exemplifies its operational model.

4. a look ahead

4.1 where IXPs meet SDN

unexpected richness in routing policies