Short answer:
Unfortunately we only pick up Webreach/SAIX traffic in JHB from upstreams who purchase transit/peer with Webreach.
Long answer:
Basically this comes down to settlement free and open peering (which 450+ networks manage to get right in SA). The only two networks in South Africa (who also have end-user services (let's call these eyeball IPs) on their networks and are not just transit networks) are Web Reach and Seacom; thoroughly stuck in the 1990s and convinced they can force ISPs to buy their transit. There was a time where these networks had a duopoly in SA, but it really isn't so anymore, and neither offer anything that would entice ISPs to pick them over the myriad of options that exist today; and strong-arming ISPs really isn't a way to get into our good books.
Some Peering and Transit background:
In it's simplest form, the internet is built of networks advertising their IPs (prefixes) to one another. How it works is that ISP A connects to a peering fabric (eg, NAP or JINX; we connect to all 6 in South Africa) and advertises their IPs to all the other peers. Sometimes a direct peering session is set up between peers. ISP B does the same. Now ISP A and ISP B can exchange traffic via the shortest possible path at a mutual exchange, without incurring direct bandwidth costs. For prefixes not advertised on the exchanges, ISPs purchase IP transit, from a network who has more peering, and so on and so forth until you get to your Tier 1 ISPs (who peer with everyone on a global scale).
SAIX/Webreach don't peer openly (which means some of their eyeball IPs aren't available directly at each exchange). For SAIX, we pick up these prefixes via two partners, but in JHB only. Things have changed a lot in recent years, there's hardly any content hosted on SAIX these days - so it's not really a measure for anything. Most content providers and all local networks peer directly at one of the exchanges (NAP JHB/CPT/KZN or CINX/DINX/JINX) all of which we have peering with directly for the shortest possible route...
The only way to peer with Webreach and Seacom (to reach eyeball IPs on their network, not anything else) is to buy overpriced transit from them (which we're really not inclined to do). Both still believe they have some sort of monopoly on internet in SA. The only people affected by their restrictive peering policies are their own clients at the end of the day.