What is the difference between ADSL, ISDN and Diginet or leased line services?
ADSL
ADSL (Asymmetric Digital Subscriber Line) is an access medium that provides the user with a broadband connection to Telkom's data network. Services offered over Telkom's ADSL service are:
- Fast ADSL (up to 384 kbps)
- Faster ADSL (up to 512 kbps)
- Fastest ADSL (up to 4096/10016 kbps)
ADSL offers high speed, flat rated connection to an Internet Service Provider or used as an access medium to Telkom Mobility that allows remote users to connect to their Virtual Private Networks (VPN's).
Telkom does not guarantee any throughput speeds on ADSL access. ADSL operates over the same pair of copper wires that ARE used for telephone service, and is provided only in conjunction with a telephone service. You can make and receive calls or send a fax and surf the Internet at the same time. You will not be billed for your connection time when you make use of any of the Telkom ADSL services.
The speeds in kbps are an indication at which the service syncs between the customers premises and the Telkom exchange and not an indication of the speed that you can expect to experience.
Detailed ADSL service profiles may be viewed here.
ISDN
ISDN (Integrated Services Digital Network) is a switched dial-up connection that enables the user to dial-up to any destination number within the network. A user can therefore access the Internet or a videoconference. Telkom does not guarantee any throughput speeds if a user accesses the Internet utilizing his or her ISDN line. You will be billed for your connection time when you make use of Telkom's ISDN service to surf the Internet.
Diginet / leased line services
Diginet or leased line services is a dedicated point-to-point connection that provide the user with an always on service. Diginet is based on carrier class Symmetrical Digital Subscriber Line technology that provides guaranteed bandwidths between any predefined destinations. The customer determines the transmission speed "throughput" of the Diginet services as they choose the appropriate speed with application. There is no traffic congestion due to other users as it is used in a private network topology. This also means that there is no sharing of bandwidth with other customers.
As Diginet is a constant bit-rate service it means that there is no slowdown of data transmission speed. Although Telkom guarantees the Diginet throughput speed it does not guarantee any throughput speeds of the Internet. When a user accesses the Internet utilizing his or her Diginet line the guaranteed throughput stops once the data enters the Internet.
I am currently a dial-up subscriber and I would like to use DSL, can I use my current username and password to access the Internet with DSL?
No, if you are either an analogue or ISDN dial-up subscriber, you will have to upgrade your service to an Internet powered by DSL service to make use of the DSL Access line. A new username and password may be assigned to you dependant on your Internet Service Provider (ISP).
Can I use my Internet powered by DSL username and password for analogue or ISDN dial-up?
It is dependant on your Internet Service Provider (ISP). Some ISP's do provide the functionality to access the Internet via dial-up on analogue lines using your DSL username and Password, but unfortunately not for ISDN.
What influences the download speed that I can expect with DSL?
Download speeds are affected by your PC performance, your access line, local network capacity, congestion on connections to remote networks, remote networks, the remote server's access line and the server performance.
As with dial-up and ISDN, DSL users share bandwidth on the Internet. Coupled with this, the performance of international servers will also affect download speeds. Also, the fact that we are situated in South Africa means that international bandwidth is purchased at a premium and is not unlimited.
Another limiting factor is the application you use your Internet connection for. This is explained in the next question.
What can I do to manage the amount of bandwidth I consume to obtain more and better use of my DSL access service?
| Activity | Usage behaviour | Minimizing usage |
|---|---|---|
| Downloading large files | Downloading files like MP3, games and software using software such as Napster. | Refrain from using automated download programs. |
| On-Line Gaming | On-line gaming can average data transfer of between 10 - 60 MByte per hour. | Limit the usage of data transfer when playing games on line. |
| Mail / News Group / Chat | Email, Newsgroups and Chat clients are used to communicate online, however when files with suffix of "avi", "jpeg", "mpeg", "gif", etc are sent they can contain very large amounts of data. | Be careful when subscribing to sites which automatically send information with large attachments. Be aware of "background" download programs |
| Fraud | Customers who do not protect their equipment by using a firewall or proxy server create a possibility for remote access to the PC and by using various programs, determining username and passwords, the PC can be used to transfer data via the owner's account. | Secure your PC by setting up a firewall or proxy server. |
| Browser Use | Automated copying of website content can result in high usage levels. | Manually select the content that needs to be copied. |
Where can I find local copies of popular files?
Telkom maintains mirrors of popular repositories at ftp.saix.net and ftp.telkomsa.net. On ftp.telkomsa.net you will find apple2, cygwin, freshrpms, gnuwin, Red Hat, and xfree86 files. Visit the SAIX entertainment page for a list of other services and files including Apache, F-secure, CPAN, Linux, Open Office, RFC, Simtelnet and Solaris.
What is the difference in Kilobit per second (kbps) with regard to the DSL access service upload and download speed and Kilobyte per second (kBps) as indicated when I download files via the Internet?
Bandwidth is normally measured in Kilobit per second (e.g. Dial-up = 56 kbps, ISDN = 128 kbps and DSL = 512 kbps). Applications like downloads in Windows will normally report speed in Kilobytes per second (kBps).
You have eight Kilobits in one Kilobyte (8 kbps = 1 kBps) therefore if you download a file using Internet Explorer, Windows will report a download speed of say 23 Kilobytes per second and this will translate to 184 Kilobits per second in bandwidth throughput obtained on your DSL access line.
What would I pay to convert from my existing service to DSL?
A DSL installation charge of R627.63 (incl VAT) will apply if a customer has an existing telephone service. Alternatively, the customer can opt for the Self Install option which is Free-of-Charge.
If a customer with an ISDN2/2a line wants DSL and circumstances permit the provision thereof, the status of the ISDN2/2a service will be converted to POTS (Post Paid Exchange line) plus DSL at the prescribed charge of R412.68 (VAT incl).
What modems do Telkom stock?
Available Modem/Router Details
Available Modem/Router User Guides
What is Fixed Wireless Broadband - WiMAX?
Fixed Wireless Broadband is Telkom's high speed WIMAX access medium. The technical description is "WIMAX - Worldwide Interoperability for Microwave Access 802.16 - 2004"
It is a wireless broadband access technology operating from a base station with a range of up to 30km to indoor/outdoor units at a customer premises. This range highly depends on line of sight conditions.
The Telkom offering is an up to 512Kbps Broadband Internet access product, similar to ADSL512.