At my job the wireless is pulling download speeds of 11mbps and uploading at 2mbps. The lan however is averaging around 2-5mbps download and 1-2mbps upload. Our setup is pretty basic, a cable modem, Cisco firewall, and two 24 port switches. Then the cable running from the patch panels to the office wall outlets. Everything is on Cat5 and the wireless router is connected to one of the 24 port switches.

We pay for 16mbps down and 2mbps up from Comcast. Any suggestions to increase the lan speeds??


  • Does that mean wireless traffic goes from you -> wireless router -> switch -> Cisco Firewall -> cable Modem -> the internet?
    – sgmoore
    Commented Jul 22, 2011 at 17:14

6 Answers 6


Not being a expert I would say that the cable or the connectors are of poor quality.


I suggest to have your cables checked by a company that has the right equipment (Fluke?). They should be able to give a detailed report on the capacity and quality of each cable and of the switches. CAT5 by itself should be able to do it, it only says something about cable quality, not about wiring quality.

Once I saw an office go from 100 Mbit to 10 Mbit after they replaced their 100Mbit hub with a gigabit switch. Huh? From the report, it appeared that the initial CAT5 cabling was non-EIA strung (all pairs were crimped as parallel, not crossed as required by EIA-B) and the cables were snugly tied to metal heating tubes using tie-wraps, making crosstalk and standing wave nodes cripple communication. Rewiring, recrimping and rearranging cables resulted in an A-grade report and a network with over 80MB/s transfer rates.

Of course, you could do your own preliminary tests by having two up-to-date computers attached through the longest path of the network, both in terms of physical distance and in node hops, and time the coping of a huge file.


As both Vaughn and Stargazer712 have eluded, the first step is with some basic troubleshooting in determining what may be the actual issue.

Are the switches manageable models? If so you should be able to review its counters which may provide some clues as well. Setting up some transfers within your local network would help establish some point of control reference to compare against.

  1. The test system should probably have its NIC setting manually set versus the default of "autodetect" which can sometimes result in mis-matches - the result being less-than-optimal line settings (speed and duplex) which performs poorly
  2. Transfers (CD to DVD sized) should be made between the test system and the wired (across both switches and maybe router, if any routing occurs within your network) as well as wireless systems for comparison

The tests should help in identifying any possible patterns (which further identifies the actual symptom(s)).


First I would verify:

Are the reporting statistics you're reading in the same unit of measure? Have you corroborated the report with your own speed test within the office, as well as a remote location capable of receiving and sending large files at a capacity greater than your own?


You first need to check the bandwidth rating of the cable modem/firewall port which is being led off to the two 24 port switches. Cat5 cables are outdated in almost every topologies and provide a maximum bandwidth of 100 MbPS. You should ensure that the ports on devices (Firewall/Modem) that provide connectivity to the two switches are at least of GBIC rating (Giga Bit Ethernet/ 1000 MbPS) else what happens is that the 100 MbPS bandwidth provided to the switches is being shared by all the 48 machines on the two switches thus giving an average of 2 MbPS effective bandwidth to each machine. The Wifi router however with an uncluttered 802.11n ( I am guessing) technology gives full usage of bandwidth to the Wireless devices.

So things you need to check first.

  1. What device provides upper connectivity to the two switches?
  2. What is the bandwidth rating of the port from which connectivity is provided to the two switches?
  3. If it is FastEthernet (100MbPS) device needs to be changed to provide GBIC (GigaBit Ethernet, 1000 MbPS) ports and connections.
  4. Upgrade your cabling from Cat5 to at least Cat5e if not Cat6.

These steps would ensure that your LAN bandwidth issue would be solved.


Congestion is my guess. You have two 24 port switches (and presumably 48 computers?), so you probably get a lot of collisions that don't happen on wireless.

That's my guess.

  • With switches the collision domains are split up. With wireless it's one large aggregate resource pool. If the wireless user is getting 11mbs, then it's likely he's the only one on it. Commented Jul 22, 2011 at 17:42

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