I'd like to set up a poor wifi network in my office for developers to test on. What is the best way to simulate real world crappy wifi? High latency? Dropped packets? low bandwidth?

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    There are many different kinds of "crappy" wifi, so you may need to be more specific. Do you mean low signal strength, high interference, airtime congestion, unbalanced power output, or any of a dozen other problems? – YLearn Jul 2 '13 at 18:39
  • mostly looking for low bandwidth high latency network conditions with/without disconnects. Maybe some packet dropping. – SAR622 Jul 10 '13 at 9:32
  • Would just dropping the signal strength help? Alternately, if you have external antenna, unscrew them a little bit... like YLearn says, it depends on what kind of crappy you're looking for. End user crappy is completely different from RF technician crappy. – Nanban Jim Sep 18 '15 at 19:35

your best bet will probably be to put a wan emulator in-between the wlan network and rest of the network. Even better if you are using multiple SSIDs, each going to its own VLAN (you'd then place the WAN emulator between the SSID's VLAN you want to break and the rest of the network.

You could then configure the emulator to create the crappy network (ie: jitter, latency, packet loss, max bandwidth, etc)

A wan emulator that i've had pretty good success with is WANem link

  • WANem looks great. Follow up question: do I need to have a machine running WANem outputting to the access point directly or can I have it setup like I would a wifi controller where the machine running WANem is just another device on the network switch and define on the router or the switch a VLAN that routes traffic through the machine running WANem? (Cisco 891 router, SG300 managed switch, AP-1602) – SAR622 Jul 3 '13 at 11:00
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    If your AP/Controller supports VLANs, I'd create a new SSID that points to a new VLAN. Put WANem int 0/0 in said VLAN, give it an IP, and make it the default gateway for clients on said SSID. Put WANem int 0/1 into a VLAN that can reach the rest of the network, and make WANem's default gateway the gateway of said VLAN. You'll need to create a static route on this default gateway pointing traffic to the SSID VLAN to the WANem int 0/1. – emynd Jul 3 '13 at 12:35
  • If I'm understanding you correctly, I need for the machine I'm running WANem on to have two network cards and to route traffic through that treating the two network cards as independent interfaces. Is there a way to connect the machine with only 1 cable and define the routing on the router to move all traffic up and down on that 1 interface? – SAR622 Jul 10 '13 at 9:38
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    from my experience, WANem requires two interfaces, so it can change the affects of traffic going over it. Anyway, if you only have a server with one interface, you could throw a hypervisor on it (vmware, citrix, etc), create the two virtual interfaces (will need different vlans), create trunk port to switch (or use router-on-a-stick). And apply the same setup as my previous comment.<br/>could also use vmware player (or even virtual box) for this: wanem can be ran off a cd/dvd (just mount the iso on the virtual) – emynd Jul 10 '13 at 15:44
  • OK. Got a box that I can put 2 PCIE network cards on. From what I'm reading it looks like it's a liveCD. Can I also set it up to run in the background of a regular Linux box? – SAR622 Jul 24 '13 at 15:26

Without knowing more about the service that is being used on top of this "crappy" wifi, it is more difficult to give suggestions.

If you are pushing HTTP traffic, then you can use a proxy software called Fiddler to simulate slow speeds or even intercept traffic to pause or modify it.

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