SAIX Routing

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jacobstone

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Does anyone on this forum know of a way that I can contact SAIX regarding a poor routing set up?

I have discovered that ADSL connections in George have a faster ping to ADSL lines in Cape Town than they do directly to each other. It would seem that all of our traffic is being routed via Cape Town before coming back to George.

This seems pretty void of logic and I'd like to just make them aware that it's driving some people up the creek over here.

Any suggestions on how I can go about this?

Also - this only started happening about 2 months ago, our pings to each other always used to be around 50ms, now it's around 100ms.
 
Hi Jacobstone,

When ADSL was initially launched everything went via jhb... CPT, DBN, george... everything.

SAIX has recently updated there regional routes, I noticed a substantial drop in latency while gaming, about 4 or 5 months ago.. +/- from 45/55ms to 18/25ms on a cape town server.

I was being routed via JHB for almost a year.

All i can say is wait untill ADSL in george reaches a critical mass, and SAIX will update the routes when it's no longer feasible to route via jhb.

I fear any amount of screaming and shouting at them will just damage your throat :(

i dont quite understand the reasoning for the bad reoute set up... i feel your pain!
 
Thanks plenty, that's interesting... I suppose SAIX don't really make their routing info publicly available?

It definitely seems that we are going via Cape Town at the moment judging from these trace routes. You can see that for George -> George and George -> Cape Town the second hop is the same in both. In the third trace route below (George to Joburg) the next hop changes.

---
Tracing from my pc in George to another ADSL connection in George:

Tracing route to *.dyndns.org [41.241.160.116]
over a maximum of 30 hops:

1 <1 ms <1 ms 1 ms 10.101.240.254
2 50 ms 49 ms 49 ms dsl-241-160-01.telkomadsl.co.za [41.241.160.1]
3 90 ms 92 ms 88 ms dsl-241-160-116.telkomadsl.co.za [41.241.160.116]

Trace complete.
---

Tracing from my pc in George to ADSL in Cape Town:

Tracing route to *.dyndns.org [41.243.43.42]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms 10.101.240.254
2 49 ms 49 ms 49 ms dsl-241-160-01.telkomadsl.co.za [41.241.160.1]
3 63 ms 62 ms 63 ms dsl-243-43-42.telkomadsl.co.za [41.243.43.42]

Trace complete.
---

Tracing from my pc in George to ADSL in Joburg:

Tracing route to *.dyndns.org [41.243.75.146]
over a maximum of 30 hops:

1 <1 ms 2 ms <1 ms 10.101.240.254
2 * * * Request timed out.
3 70 ms 70 ms 70 ms dsl-241-192-01.telkomadsl.co.za [41.241.192.1]
4 82 ms 80 ms 81 ms dsl-243-75-146.telkomadsl.co.za [41.243.75.146]


Trace complete.
---

But what I don't understand is that it wasn't always this way!? I used to get 40 - 50ms ping between ADSL connections in George, why on earth would they have changed it?
 
The reason is because of the tiered design of Telkom's ADSL network; 1st = ATM, 2nd = IP.

The DSLAM concentrator (that your ADSL line connects to) in your local exchange is connected upstream to a regional IP termination router via ATM. As these routers only sit in the major metro centers, traffic between any 2 IP addresses has to pass through a regional router to be properly IP routed.

This results in traffic between 2 George ADSL users being routed through Cape Town's regional router.
 
So Roman, what you're saying is that it's always been routed this way and now all of a sudden, maybe because of congestion, it's slow?

I just don't get why it's so consistently slow.

Damn saix.
 
plenty said:
+/- from 45/55ms to 18/25ms on a cape town server.
Click to expand...

Damn, there is something wrong with my connection then! I get ping replies from work in Constantia to my home pc in sunningdale, 40km away @ 90ms. All within the Cape Town region.

A far cry from 18/25 :(
 
jacobstone said:
So Roman, what you're saying is that it's always been routed this way and now all of a sudden, maybe because of congestion, it's slow?

I just don't get why it's so consistently slow.

Damn saix.
Click to expand...

I think what he is saying is correct. But what I'd like to add is that maybe with the higher uptake in maybe your area the routers and routing protocols have determined that it would be a lower metric (more feasible) to go through Cape Town. Don't know what routers or routing metric telkom uses but this is my opinion of the situation.
 
UnUnOctium said:
your area the routers and routing protocols have determined that it would be a lower metric (more feasible) to go through Cape Town.
Click to expand...
As I mentioned before, the path between your ADSL modem/router and Telkom's termination router is encapsulated in, and transfered via ATM.

ATM has no concept of routing & metrics, all paths are statically configured PVCs (permanent virtual circuits). If the capacities of the termination routers in one area are exhausted Telkom can sometimes configure your PVC to a router in another area e.g. you live in JHB but use a DBN termination router.

Only after the termination router (you've been configured to use) is your traffic pure IP, and is routed via prefered metrics on the SAIX national IP backbone to where ever its destined.
 
Ah right, so an ICMP trace route is not much of a test for this seeing as it's bouncing around as a Layer 2 frame for a while before actually becoming an ICMP packet?

Sigh, I guess I'll just have to live with it, I'm pretty sure there is no getting through to SAIX about it. I guess they just determined that 80% of the traffic is for outside of George or International so route everything that way.
 
Ok, whoever from SAIX was reading this post - thanks a stack for sorting it out. Pings are back down to normal!

Pings to Cape Town still faster (30ms - 40ms but it's of no real concern, at least getting 50ms - 60ms between ADSL connections in George again!

Awesome :)
 
Ah man, it was working perfectly for like a week, today it's gone crazy again?

To the guy from SAIX that fixed it previously, help please!

Pinging *.dyndns.org [41.243.54.148] with 32 bytes of data:

Reply from 41.243.54.148: bytes=32 time=137ms TTL=253
Reply from 41.243.54.148: bytes=32 time=136ms TTL=253
Reply from 41.243.54.148: bytes=32 time=136ms TTL=253
Reply from 41.243.54.148: bytes=32 time=135ms TTL=253

This is pinging from George ADSL to George ADSL!
 
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