IXP? What is that????

An IXP (Internet Exchange Point) is a place that allows the interconnection of autonomous networks, and the exchange of data and content between them.
This is the definition in the program for the Angonix Forum 2016. But instead o giving you my own definition, I’ll start by explaining why we need exchange points.

Internet Access

Lets start with a simple conceptual representation of what is internet access to a user. Suppose we have 4 internet providers Mocivel, Utinel, VTCabo and PAZ Fibra. These 4 providers sell internet access to their customers but they are also customers of other bigger providers to whom they pay transit to be able to get to the “internet”.


Considering international fiber optics communications and ignoring the access network, packet “travel” time (latency/delay) from the user to most of the content is on average 90 ms each way for a total of 180 ms (to Europe/US). Latency is one of the big factors in the perception of speed and overall experience in the internet.

And what if I want to talk to my neighbor?

But what happens if a Mocivel customer wants to connect with customers from Utinel and VTBaco?? Or see a movie from PAZ Fibra?

It’s clear in the diagram that, without an alternate connection between providers, traffic between customers that may even be neighbors will have to go around the world. The worst part is that in this case average latency will be even worse than before, with double the distance between endpoints. It will be 180ms one-way and 360ms for the return.


comunicacao sem provedores

Communication between providers without an IXP

The solution can be direct connection between providers that think they may have the need to exchange traffic through peering agreements.

Ligação entre provedores

Connection between providers

But what happens when 2,3 or more providers com into play? The well know full mesh, where each provider must have a connection to each one of the other providers and the total number of connections would be n(n-1)/2 (n = number of providers)

ISP full mesh

ISP full mesh

Big mess!!!!

Here comes the IXP

That’s how I think about an IXP. A “local internet”. Getting back to the definition at the beginning of this post:

An IXP (Internet Exchange Point) is a place that allows the interconnection of autonomous networks, and the exchange of data and content between them.


The existence of an IXP in any country or region makes it possible to have communication between networks (not only providers) using single local links with smaller latency. Local links are not only “faster” but also cheaper, allowing operational cost savings for  the providers, companies connecting to the IXP.

But Facebook and Youtube are not in Angola!

Yes, the big datacenters and content providers are not in Angola. Websites created by little curious kids are not in Angola. Most of angolan companies websites are not in Angola. Even websites for some government companies and institutions are not in Angola. If that’s the case why should I connect with other angolan providers if 99% of my traffic is international?

Well, we have to bring the internet to Angola. IXPs and ISPs make partnerships with companies that have the information we are looking for and they bring their servers and content locally. Google (=Youtube), Facebook (=Instagram), Whatsapp, Netflix, Akamai, Cloudflare, Amazon (last 3 are CDN‘s) are good examples of companies that would benefit us greatly if they had content here in Angola.



With content hosted here in Angola all messaging, images, videos and voice calls would be a flash.


It’s all pretty and beautiful. But do we have any IXP in Angola? And if there is one, is it worth it connecting to any of them? Yes and Yes. Actually, 2 x Yes and Yes.

Even though Angola Cables and Angonix have been doing much more marketing, there is already an IXP in Angola since 2006.

ANG-IXP, managed by members of AAPSI (Associação Angolana de Provedores de Serviços de Internet – Angolan ISP Association) had a recent restructuring and has 16 members connected. In 2009/2010, an agreement with Google had it installing servers for the Google Global Cache (GGC) that allowed local access to Google’s services, Youtube included.

Angonix started operation in March 16, 2015, has 11 members and many partnerships with content providers and CDNs. There aren’t many details of who the partners are but Angonix presented at the forum traffic statistics averaging 3.1 Gbps monthly and 4.4 Gbps peak making it the 3rd biggest IXP in Africa (considering the peak) behing NIXP (Nigeria) and the NAP of Africa (South Africa). What’s interesting is that if we considered the monthly average, Angonix would in fact be 2nd behind the NAP of Africa.

And the future? Will there still be 2 IXP? Is there really a need to have them in Luanda (Angola’s capital)? I won’t be the one to answer these questions.


This post was originally published in this blog March/2016 in portuguese.


You can read more:

AAPSI Associação Angolana de Provedores de Serviços de Internet – Portuguese

Angola-IXP (unavailable when this post was published) – Portuguese

Angonix – English

Estatísticas de tráfego Angonix – English

Internet Exchange Points (IXPs) – Scalable Infrastructure Workshop AfNOG 2008

Scaling IXPs – Scalable Infrastructure Workshop AfNOG 2008

The Value of Content Distribution Networks and Google Global Cache

What is a CDN?



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