GGOD

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May 29, 2017
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So i got a problem with my DLink-2750U router in that the upload /download speeds randomly (many times a day) get really low and/or becomes nul until either i disable then renable wifi on my phone or pc or i reboot the router altogether

at first i thought that this may simply be a problem with my ISP ,so i contacted them ,they came and verified all the cables ,configuration on their end etc ... and said that everything was ok on their end. Later on, what made me think that the problem is with my router is that sometimes even local file transfers or just trying to access the router's config page takes ages ...so can anyone point for what to do ? Thank you.
 

Ralston18

Titan
Moderator
Try swapping in known working (at speed) Ethernet cables wherever in the connection path(s) they are being used.

Cat 5e, no flat cables, no Aluminum/copper clad cables. AWG 22-24.

= = = =

This router?

https://www.dlink.ru/mn/products/3/2383.html

[Verify that I found the applicable manual.]

Look in the router logs:

https://usermanual.wiki/D-Link/DSL-2750U/pdf

Reference Page 81.

You may need to configure the logs and then go through a few speed changes to capture a few (if any) errors.
 

GGOD

Reputable
May 29, 2017
67
2
4,545
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Try swapping in known working (at speed) Ethernet cables wherever in the connection path(s) they are being used.

Cat 5e, no flat cables, no Aluminum/copper clad cables. AWG 22-24.

= = = =

This router?

https://www.dlink.ru/mn/products/3/2383.html

[Verify that I found the applicable manual.]

Look in the router logs:

https://usermanual.wiki/D-Link/DSL-2750U/pdf

Reference Page 81.

You may need to configure the logs and then go through a few speed changes to capture a few (if any) errors.
yes its the router you mentionned ,but i didnt quite get this part of your answer

(Try swapping in known working (at speed) Ethernet cables wherever in the connection path(s) they are being used.

Cat 5e, no flat cables, no Aluminum/copper clad cables. AWG 22-24.)

would you please ellaborate more ?
 

Ralston18

Titan
Moderator
Swapping cables:

Very likely that you have a number of network devices connected by Ethernet cables. Modem ---Ethernet cable ---> Router ------Ethernet cables to -- ---- > wired devices such as computers, printers, switches, online storage etc....

So what you need to do is to replace each cable along the path with a known working (at speed) Ethernet cable. Between Modem and Router for example. If the speed returns to normal then the original cable may be bad. If speed does not return, then put the original cable back and again use the known working cable to replace the next Ethernet cable in the line - between router and your computer.

Objective is to methodically work through all of the cables to determine if one is bad. It could be true that multiple cables are bad but unlikely unless all of them happened to have been purchased from some low quality source.

Look at each plug - it will not take you too long to get a sense that some cables are better made that others by just looking how the wire conductors fit into the plug. How neat, square, and secure the plug is to the wire. There are standards as to how the wires are actually ordered: 568A and 568B.

= = = =

Ethernet cables are round and contain 4 pairs of twisted wires. Each pair twisted with its' counter part and all four pairs also twisted. Good quality Ethernet cables meet certain standard for both twisted and composition. The conductor should be pure copper and a certain diameter that being 22-24 AWG (American Wire Gauge).

Cheap cables are not twisted, made of aluminum with just a copper "cladding", and probably thinner wire than the Ethernet specs require.

Wires can be un-shielded, shielded, stranded, or solid.

Flat cable is usually not twisted, likewise thinner conductors, and overall not suitable for use.

You can easily google for more information about Ethernet cables.

For example:

https://www.comms-express.com/blog/ethernet-cables-explained-all-you-need-to-know/

https://www.tripplite.com/products/ethernet-cable-types

Many other links can be found and some are mostly just advertisements. Some simply are hype and promoting cables that are "rated" for specs not even yet approved.

Ethernet cables have their specs continuously printed along the length of the cable. But the counterfeiters and low end manufacturers simply print bogus information....
 

GGOD

Reputable
May 29, 2017
67
2
4,545
1
Swapping cables:

Very likely that you have a number of network devices connected by Ethernet cables. Modem ---Ethernet cable ---> Router ------Ethernet cables to -- ---- > wired devices such as computers, printers, switches, online storage etc....

So what you need to do is to replace each cable along the path with a known working (at speed) Ethernet cable. Between Modem and Router for example. If the speed returns to normal then the original cable may be bad. If speed does not return, then put the original cable back and again use the known working cable to replace the next Ethernet cable in the line - between router and your computer.

Objective is to methodically work through all of the cables to determine if one is bad. It could be true that multiple cables are bad but unlikely unless all of them happened to have been purchased from some low quality source.

Look at each plug - it will not take you too long to get a sense that some cables are better made that others by just looking how the wire conductors fit into the plug. How neat, square, and secure the plug is to the wire. There are standards as to how the wires are actually ordered: 568A and 568B.

= = = =

Ethernet cables are round and contain 4 pairs of twisted wires. Each pair twisted with its' counter part and all four pairs also twisted. Good quality Ethernet cables meet certain standard for both twisted and composition. The conductor should be pure copper and a certain diameter that being 22-24 AWG (American Wire Gauge).

Cheap cables are not twisted, made of aluminum with just a copper "cladding", and probably thinner wire than the Ethernet specs require.

Wires can be un-shielded, shielded, stranded, or solid.

Flat cable is usually not twisted, likewise thinner conductors, and overall not suitable for use.

You can easily google for more information about Ethernet cables.

For example:

https://www.comms-express.com/blog/ethernet-cables-explained-all-you-need-to-know/

https://www.tripplite.com/products/ethernet-cable-types

Many other links can be found and some are mostly just advertisements. Some simply are hype and promoting cables that are "rated" for specs not even yet approved.

Ethernet cables have their specs continuously printed along the length of the cable. But the counterfeiters and low end manufacturers simply print bogus information....
i have multiple devices connected to my modem (around 8 or so) ,but all of them are connected through wifi ,im not using Ethernet at all ,so i dont know if this can help ?
 

Ralston18

Titan
Moderator
Typical network connectivity:

ISP ---- DSL, fiber, coax cable ----> Modem ----- Ethernet cable ----->[WAN Port] Router [LAN ports] ---- Ethernet cable(s) ------> wired devices

and

~~~~ wireless ~~~~> wireless devices.

The modem and router may be combined which, appears to be so in your network.

There could also be a problem with your DSL connection. Take look at the connections coming into your residence.

The ISP cable likely leads to a small box referred to a splitter or filter. One telephone cable in, two out. One cable out goes to your telephone(s). The other cable leads to the D-Link Router. Splitters can and do go bad.

FYI:

https://www.iprimus.com.au/technical-support/adsl/filtering-phone-lines-for-adsl/

= = = =

What did you find, if anything, in the router's logs?

Try turning off all but one wireless device. Determine if network speeds/performance is as expected. If so then turn on a second wireless device.

Continue doing so, device by device to determine if the problem begins at some certain number of devices.

Then repeat the process but change of the order of device re-connections. Could be that one particular device is causing the problem.

Overall, the circumstances of your wireless network may be that between high bandwidth demand, reception/interference problems, and devices coming on and going off the network (for whatever reasons) is just more than the router can handle.

If at all possible use wired connectivity for some devices.
 

GGOD

Reputable
May 29, 2017
67
2
4,545
1
Typical network connectivity:

ISP ---- DSL, fiber, coax cable ----> Modem ----- Ethernet cable ----->[WAN Port] Router [LAN ports] ---- Ethernet cable(s) ------> wired devices

and

~~~~ wireless ~~~~> wireless devices.

The modem and router may be combined which, appears to be so in your network.

There could also be a problem with your DSL connection. Take look at the connections coming into your residence.

The ISP cable likely leads to a small box referred to a splitter or filter. One telephone cable in, two out. One cable out goes to your telephone(s). The other cable leads to the D-Link Router. Splitters can and do go bad.

FYI:

https://www.iprimus.com.au/technical-support/adsl/filtering-phone-lines-for-adsl/

= = = =

What did you find, if anything, in the router's logs?

Try turning off all but one wireless device. Determine if network speeds/performance is as expected. If so then turn on a second wireless device.

Continue doing so, device by device to determine if the problem begins at some certain number of devices.

Then repeat the process but change of the order of device re-connections. Could be that one particular device is causing the problem.

Overall, the circumstances of your wireless network may be that between high bandwidth demand, reception/interference problems, and devices coming on and going off the network (for whatever reasons) is just more than the router can handle.

If at all possible use wired connectivity for some devices.
i'll try replicating all the steps you mentionned Asap and get back to you with the answers i found ,thanks for taking the time to answer my question
 

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