Supra Telecom: Home - Local Telephone - Long Distance

1) My ADSL has stopped working, help, what do I do, how can I find out what's wrong?

There are a number of reasons why your ADSL service could stop working, below are some steps that you should go through to 'troubleshoot your service' to see if we can find out what's going on.

1. Reboot your ADSL modem (often they hang or stop working for many different reasons).
2. Wait about 1 minute, then check to see if you have line-synch.
3. Check that your login name and password are correct.
4. Check to see what error is coming up when you cannot log in.
5. Check that your ADSL modem is connected correctly and that you have your filters and splitters connected correctly. (If you have an unfiltered phone this can cause your ADSL to stop working)

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2) I am losing Line Synch - what might be causing that, and what should I check before logging a fault?

When your ADSL modem or router loses line synch it means that it’s not able to talk correctly to the DSLAM at the exchange (the other end of your phone line). There are a number of reasons why this could be happening. Here are some things you should check before logging a fault with our helpdesk. These are in order of how you should check them, if one solves your problem then you need not progress to the next.

1. Check that you don't have any unfiltered phones connected to your ADSL line. If you have unfiltered phones connected, these can disrupt your ADSL signal. Connect filters to all of your phones.

2. Check that your line filters are not faulty or that you don't have a noisy/faulty phone or adapter on your phone line. Try a different line filter on your phone line. Unplug everything from your phone line, all filters, all phones, all adapters, and plug ONLY your ADSL modem in, and see if it keeps losing synch... If it stops losing synch, then you have a faulty ADSL Swapper and/or Line Filter on your phone line.

3. Failing the above, log a support request with Footprints, and tell them what you have tested, this will help speed up their diagnosis of what the possible problems are. At this stage it is most likely a 'line-level' problem which we will need to get FDN to check for us.

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3) How can I check that my ADSL Line is working at the right speed?

There are several things you can test to see if your ADSL line speed is correct.
Firstly try out FDN’s speed tester: http://speedtest.fdn.com/

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4) My ADSL drops out when the phone rings - why?

This usually happens when an ADSL line filter is not connected correctly to one or all of your phones.

Check that all of your phones that are attached to the line that has ADSL connected to it have filters and/or are on the correct plug of an ADSL splitter.

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5) My phone line is noisy when my ADSL is in use - how can I improve that?

This often happens when you don't have the line filters connected correctly to each phone in your house. Check that you have the line filters connected correctly.

There are also some incompatibilities between certain ADSL filters and certain Phone manufactures. One solution is try different ADSL filter, or try connecting two in series (one into another).

If you have an older analogue cordless phone, your DSL modem could be causing electronic interference if it is in close proximity to your cordless phone aerial. Shift your phones base station further away from your ADSL modem, or get a digital cordless phone.

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6) If I am seeing ADSL performance problems, how can I diagnose and fix them?

The Internet is not a single network; it is a complex mesh of many networks. There are a lot of potential causes of periods of low performance when using any Internet access service.

We'll explain (below) some of the more common ones, provide some guidance on them, and (if pain persists), tell you how to report a potential performance issue to our helpdesk, with enough information to assist them in diagnosing the issue and assisting you in the most efficient manner possible.

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7) What do Latency, Packet Loss and Transfer Rate mean?

First, let’s define some terms that are relevant to the process of discussing performance issues.

Latency: Latency is the period of time taken to move information from one location to another - it is the delay in moving a packet of data. This is most commonly expressed by ADSL users as their 'ping time' - which is actually a measure of the latency in moving a packet from one location to another and back again - otherwise known as the Round Trip Time.

By way of analogy, you might think about latency as being like the elapsed time it takes to drive to a destination and return home again.

Packet Loss: Packet loss refers to the percentage of packets which, when transmitted in the network, fail to reach their destination. Packet loss, as indicated by tools such as 'ping', indicates the loss in either the outbound or the return direction, and does not indicate the location or direction in which that loss occurred. It is commonly referred to as a percentage, with 0% loss meaning that all packets were carried to their destination successfully.

By way of analogy, you might think of this as the likelihood that you will actually manage to drive to your chosen destination and get home again (!).

Note that the TCP protocol uses the loss of packets as part of its rate control and adjustment mechanisms, so that some (small) level of packet loss is actually normal during TCP based data transfers.

Transfer Rate: (often called 'download speed' or 'throughput'): This is the rate at which data is transferred over a connection. It is often expressed as a speed in KiloBITS per second or in KiloBYTES per second.

It is common to confuse these, as they can both be abbreviated to just 'K/sec', and its important to be clear on which one you are referring to at a given time.

It is also important to understand that transfer rates can be expressed in terms of total data rate (including various overheads, like ATM cell tax and IP packet header data), or payload data rate (the resulting download rate for the data you actually wanted to transfer).

By way of analogy, you might think of this as the speed at which you can drive somewhere - something which is constrained by the current speed limit, and also by the potential presence of other cars on the road (and consequent traffic jams!).

See here for an indication of reasonable expectations in terms of transfer rate in an ADSL service.
The factors that affect download performance are many and varied, and latency, packet loss and transfer rate are interdependent.

These three factors matter differently to different people.

Someone wanting to play interactive games may care more about latency and packet loss than they do about transfer rate. In particular, latency affects the responsiveness in game play - in particular it defines the delay (or 'lag') between instructing an in-game character to take an action, and seeing the results of that action reflected back to you by the game server.

Naturally, any packet loss also adversely affects game play.

However, transfer rate (throughput) is not always affected by high latency or even by moderate packet loss. Therefore, the responsiveness of the Internet in terms of web browsing, access to email, and similar functions, may not be significantly affected by higher latency.

The Internet protocols used for most data transfers (TCP) are designed to automatically adapt to the latency and packet loss present in any given end-to-end network path, and to deliver the best possible transfer rate under current circumstances. They are adaptive protocols and they benefit from 30 years of performance tuning in this respect.

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8) What is an MTU and why does it matter?

Your MTU, or Maximum Transmission Unit, is a measure of the configured packet size that your computer uses when sending packets of data to other computers. In the context of ADSL, an MTU is commonly set somewhere between 1400 and 1500 bytes.

There turn out to be some critical sizes for the MTU, and a variety of performance problems can be caused (for different, but inter-related, reasons) if your MTU is set too high. Contrary to what might seem sensible, lowering your MTU can actually raise your data transfers speeds (up to a point) as a result.

The various adverse issues possible when your MTU is too large can include:

• Very low download speeds on an otherwise 'clean' data path (no packet loss, low latency).

• FTP or other file downloads which stall (stop working) after just the first 1-2 kilobytes
downloaded (including the downloading of a server file listing in an FTP client, which is actually just another file download and is subject to the same issues)

• Situations where some web or FTP sites work fine for downloads, but others operate slowly or not at all (the difference being based on whether the remote site is interacting with the network in a manner which makes this issue show up or not). In particular, some of these sites may be encountering a problem related to Path MTU Discovery which is being made worse by your MTU being too large.

The solution is to try lowering your MTU to see if your issue(s) are resolved in this manner.
This webpage and utility may assist in this case: http://www.dslreports.com/front/drtcp.html

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9) Why is my ping time (latency) higher if my ADSL line speed is lower?

It is in fact normal that the speed of your ADSL line plays a part in the overall latency of your ADSL service when communicating with other hosts on the Internet. You can, therefore, lower your latency to all destinations by moving to a higher line speed, if you wish to.

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10) Does other activity on my ADSL service affect my download and/or upload rates?

Yes, it does.

If you run any sort of peer-to-peer file exchange software, for instance, this can completely consume the bandwidth in your ADSL service to the exclusion of your own additional use of that service.

You can even find that after you have stopped using a Peer-to-Peer service, that your performance remains low, due to other P2P software users trying to connect to your system (which can continue for some time after you have disconnected from some P2P 'networks'). Even their attempts to connect to you are consuming capacity in your ADSL service.

It is also important to appreciate that concurrent uploads have a very significant effect on your available download speed. This effect is especially pronounced with ADSL services (compared to other, symmetric forms of Internet link).

ADSL services are more significantly affected because all data transfers need to send data in both directions in order to work properly. When you are 'downloading' something, there is a stream of 'ACK' (or Acknowledgement) data packets flowing in the return direction, which manage the data flow and ensure that it is working properly.

The bandwidth required by those ACK packets is typically equivalent to around 1/4 to 1/8th of the transfer rate you are achieving in the 'download' direction (as a rule of thumb - this is actually subject to some significant variation for a number of reasons).

As a result, if you are downloading at (say) 512 kilobits per second, you can expect to see 64-128k (i.e. up to 100%) of the 'upload' direction in a 512/128 ADSL service being consumed as well.

If you then decide to upload a file at the same time, that file upload actually slows the download because it slows down the ACK packets - and slowing those ACK packets down causes the entire data transfer to slow down.

It is the asymmetry in the ADSL line speeds which makes the effect more severe in the ADSL situation. ADSL is optimized for fast download speeds.

You should expect download speeds to be very seriously impacted by any file uploads that you may be undertaking at the same time. This is a normal consequence of the design of ADSL services.

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11) Can my ADSL device actually get slower over time?

Actually, some of them can!

ADSL devices have to work with copper phone lines which are not perfect transmission paths by a long shot; The ADSL device actually works out which parts of the 'spectrum' are useable on your line, and confines its activity to those parts.

Normally there are enough 'good' spectrums to let your ADSL service run at its full rated speed.

However, some lines can encounter periods of time when the copper lines are degraded in quality by external factors (for instance, in some parts of the Telstra copper network, the quality of copper lines is adversely affected after rain, if some of that moisture works its way through defective or worn out insulation around the copper wires in your street).

ADSL devices compensate for such situations by reducing their effective throughput (confining themselves to those parts of the spectrum that are still working).

However, it appears that some ADSL devices don't necessarily 'spring back' and start to use the entire available spectrum again once the line problem has cleared. So those devices may remain 'slow' even when the copper line is fine again.

As a result, it is worthwhile power cycling your ADSL device if your performance has degraded noticeably, to see if this improves your transfer rates once the ADSL device has re-connected to the network.

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12) Can software drivers in my PC affect my transfer rate?

Yes, some of them can. We recommend the use of Ethernet based ADSL devices because this minimizes the requirement to have any special driver software loaded into your computer to use ADSL.

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13) If I see periods of time (say 5-20 seconds) of no throughput, what might that mean?

It probably means you are suffering a complete drop-out of your ADSL service - that it is losing contact with your exchange and having to re-synchronize itself and re-establish its connection.

You should consult our FAQ about line synchronization loss to understand and check on the possible causes for this happening. Most of these issues can be resolved relatively simply.

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14) If I feel that performance is not adequate, how can I report it to you?

The best thing you can do if you feel that you are encountering performance on your ADSL service which is below your expectations is as follows:

• First, wait a little while. The Internet is not one single network; it is a global network of networks. It is entirely normal that there will be periods when performance to some destinations will be lower than usual, due to factors beyond the control of your own ISP. Don't jump at every minor 'blip' in performance - because they'll most likely be gone again by the time that you report them. And they're just a part of life on the Internet. This is the flip side of the Internet being such an affordable and accessible network.

• If 'pain persists', you next need to make sure that your expectations are realistic. Consider the issues noted above in this FAQ - you can't get something for nothing, so for instance if you are uploading a file, you should expect downloads to be slower.

• If you have left a P2P connection program online, or if you are running any other sort of 'servers' on your computer, you should expect these to adversely affect your performance.

• If you still feel that there is something wrong, well, there may well be - and we may well be able to provide advice and assistance with it.

If you wish to report a performance related issue to us, we're happy for you to do that. All you need to do is ensure that you are as specific and accurate as possible in your report.

Please open a report with us online, using the support ticket-opening tool on the FDN web site, as this provides us with documentary information and a definite timeframe and issue to track. You should feel free to call up later and discuss the issue if you wish, quoting the tracking number assigned when you open such an issue with us.

In that performance report, ideally, we would prefer that you provide the following information when reporting a performance related issue:

• What specifically is the problem you see?

• The timeframe over which this issue is occurring (does this happen sometimes - or just during the evenings, or is it something that is present all the time). Also, how long has this been happening for, and (if possible) when did it start happening?

• Your FDN username (so we can track back to your account information and check it)
• The IP address that you have currently been allocated by the network. This helps but it isn't mandatory.

• If you are familiar with how to use the 'ping' and 'traceroute' tools on your computer system, it is very very helpful if you can provide the results of running a 'ping' and a 'traceroute' to one or more network destinations which help to illustrate the issue that you are seeing. In the absence of ping and traceroute data, we may not be able to provide much guidance regarding the resolution of your problem.

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15) Are there any Ports Blocked?
• No

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16) What is the minimum speed I should be getting?

Speed are “up to” 1.5 or 3.0 so the minimum speed will be:
1.5 = the minimum will be 256
3.0 = the minimum will be 512

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17) What are the POP and SMTP servers for me email?
Pop: mail.stis.net
Smtp: mail.cleartel.net

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18) How can I access my email through the web?

http://webmail.stis.net/

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