[asterisk-tech] Telkom/087 links

HILL David David.Hill at alcatel.co.za
Wed Jun 28 13:42:32 SAST 2006


As far as I am concerned when the interconnection is SS7 there is no RTP
traffic, it is TDM and you will interconnect at E1 level sending TDM voice
into Telkom. I guess it is possible to use Sigtran M2UA or M3UA to carry the
SS7 over IP to the softswitch, but the softswitch is Telkom's and this will
happen at Telkom's Media Gateway or Signaling gateway (if connecting to an
STP network in the traditional TDM case) and point towards their softswitch
- never from outside their network. This media gateway will then again
convert to VoIP (RTP) and how Telkom transport the RTP within their network
is their problem and we will never know the topology of their internal

The only solution to this is for Telkom or ICASA or anyone to make a proper
IP-IP switch for interconnection of VAN's and not to use SS7 between VoIP
operators. This is why I mentioned Transtel's solution some time ago and
pointed everyone at Angus Hay. They have an IP-IP POI for VAN's and suchlike
(like a peering point in the internet world) and a SS7 interconnection to
the current operators. This might still be worth exploring.


-----Original Message-----
From: tech-bounces at asterisk.org.za [mailto:tech-bounces at asterisk.org.za] On
Behalf Of Steve Davies
Sent: Wednesday, June 28, 2006 1:02 PM
To: Asterisk Tech
Subject: Re: [asterisk-tech] Telkom/087 links

On 28 Jun 2006, at 12:29, HILL David wrote:

> The IP case will clearly be different because there is only 1  
> softswitch,
> but of course this will only handle signaling traffic, where  
> exactly the
> actual E1's will live is up for debate. I am assuming that they  
> will place
> trunking media gateways at certain points and most likely not force  
> VAN's to
> connect to all of them, but apply different rates if they have to  
> trunk the
> call themselves. Normally long distance in Telkom means > 50km and  
> even
> calls within the same major area code (like 011) can be long distance.

There's an interesting clash of telco and internet culture here.

There is no current IP product for sale in South Africa that charges  
different amounts for traffic depending on where the end point is in  
the country.
(In fact, often for us Capetonians, traffic is tromboned to Joburg  
and back for the network operators' convenience)

So on what basis will there by a larger charge to send RTP traffic to  
a gateway in Cape Town as compared to a gateway in Gauteng?


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