[ppml] Policy Proposal 2003-15: IPv4 Allocation Policy for the Africa Portion of the ARIN Region
gregm at datapro.co.za
Wed Oct 1 18:38:43 EDT 2003
> Cleverly using traceroute, I find that BotswanaNet.bw has connectivity
> through MegaISP.za, so I call up MegaISP.za and explain my plight.
> They sympathize with me and the money I offer them, and they allocate
> me a /22 so I can now number all of my equipment, and we set up a GRE
> tunnel (to an address from my .bw IP space) so I can route that /22.
> However, I still can't multihome, because AnotherISP.za is not going
> to accept MegaISP.za address space coming from me.
I'd like to clarify this. As Rosi mentioned, many ZA ISPs will allow you to
advertise another providers address space to them if that other provider
consents. In fact, I recently had discussions with Rosi on such a topic. I
was able to deal with my client's request really quickly because I'd met
Rosi before, knew to speak to her and we were on good terms despite working
for competing companies.
The problems I've seen with this, however, are:
1. You cannot just accept announcements of another ISP's address space
without their consent. Eg. In the aforementioned case, the client had
cancelled service and the addresses he wanted me to accept were no longer
allocated to him!!!
2. Most ISPs only advertise their supernet aggregates upstream. If you're
trying to multihome, this causes the route to be preferred by your other
upstream provider since the announcement doesn't form part of their
supernets and is more specific down that path.
3. ZA has a pretty competitive ISP industry, signficant routing expertise,
and a small enough ISP industry for us to know who to contact. In many other
parts of Africa, there are anti-competitive forces at play, politics, lack
of technical understanding, etc. Also, if you're multi-homing between ISPs
in multiple countries, you cannot expect that the ISPs will be as
co-operative. I may co-operate with Rosi regarding a mutual client because I
trust her and the ISP she works for. If, however, an ISP I'd never heard of
asked me if they could announce my address space on behalf of a mutual
client, I'd be very hesitant because I'd have almost no guarantee that if
the client cancelled their service with me that I'd be able to recover that
I hope this clarifies why it is generally not practical to multi-home
without your own address allocation.
> To compound the problem, either A) I can't afford a leased line to
> either big ISP or B) Botswana law prohibits me from using another
> provider. I may actually be breaking the law by using non-Botswanan
> address space.
I stand to be corrected on this, but to the best of my knowlege there is not
a single African country that regulates how you - as an ISP - route your
traffic or obtain addresses.
In fact, the problem is that most communications legislation is so old or
backward-thinking that its restrictions are specifically aimed at upholding
existing monopolies which tend to be around telco services.
So as an ISP, your typical restriction is that you have to buy your
leased-line from the monopoly telco. This gives them the leverage to refuse
to provide you with a leased-line to an upstream ISP in another country and
force you to buy IP transit through them.
> This is the most common configuration in sub-equatorial Africa?
I don't believe this to be the case. In many situations, the legislation is
reasonable enough to allow you to connect to whomever you like. However,
where it is hopeless is in price control. This means that the monopoly telco
in almost every African country will sell you IP transit for a fraction of
the cost of a leased-line to another IP transit provider in another country
(typically 1/10th to 1/100th). In this way, they never have to refuse to
provide service and risk legal challenges, because they simply make sure
that any ISP who purchases an international leased-circuit will pay so much
that their charges to clients for IP access will have to be 10-100 times as
much as the telco's.
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