Columbia University

Faculty of Arts and Sciences

Working from Home: WiFi/Network Considerations

Internet Speed (Bandwidth) Concerns for Zoom/Remote Work:

  • "Bandwidth" refers generally to the maximum rate at which data can be transferred over a network. With respect to home internet service, the bandwidth you pay for from your Internet Service Provider (ISP) is always a maximum, and not necessarily your actual obtained speed. Many internet plans have different "downstream" and "upstream" speeds. Downstream is data that is download from the internet to your device. Upstream is data that is uploaded from your device to the Internet. In an application like Zoom, downstream data will include the video and audio of all other participants in the meeting, while upstream data will be your own video and audio stream which is sent through the network to Zoom.

  • You may check your effective bandwidth at or (it can be helpful to compare the two).

  • Do I need faster internet to use Zoom? Zoom is very flexible when it comes to bandwidth -- visit the Zoom bandwidth requirements page -- and recommends upstream connection speeds of 1.5-3.0Mbps for optimal performance in group meetings with HD video quality. If your connection speed drops below these thresholds, your video quality will be automatically adjusted to keep you in the meeting. Most home internet packages are at least 25Mbps downstream/5Mbps upstream, and your home internet package should be at least 10Mbps down/5Mbps up in order to use Zoom effectively. Keep in mind that there is a difference between what you pay your ISP for, and what you receive -- you are not guaranteed to receive the full speeds that you pay for. If there is a large discrepancy between your effective speed (tested with the above sites) and the speed you pay for, please reach out to your ISP.

  • How much bandwidth do I need? A&S recommends that your internet package from your ISP be ~25Mbps downstream and 5Mbps upstream for one individual. If your network has multiple individuals working from home or family members who are engaged in distance learning, then this may necessitate a faster package from your ISP. Please use the speed tests above as a gauge to determine what your speeds are like during the work day. Please also keep in mind that increasing your downstream internet speeds from 100Mbps to 400Mbps is very unlikely to impact the quality of your Zoom experience. Zoom only uses ~3.0Mbps for HD video and audio.

  • Most home internet speeds far exceed the downstream requirements for Zoom. If you can stream Netflix, you can use Zoom successfully.

  • If you have a WiFi router, always try to position yourself as close to the router as you possibly can. This will ensure that you have full signal strength, and will limit the impact of any WiFi interference that may be degrading your connection speed.

  • We have received reports of Zoom struggling under heavy load during the workday. You can check the current network status of Zoom to see if you are experiencing a known issue. Please note that this site may not list all issues. When there is network congestion, users will typically see degraded or frozen/choppy video feeds. Audio is typically not affected or must less affected. In situations where Zoom is the bottleneck, please understand that you will have limited ability to improve the situation -- you may need to have a plan to adjust your teaching strategy or reschedule an administrative meeting if connection quality is very low or unstable.

  • For non-Zoom Work From Home scenarios: in most web-based applications, connection speed is not a pressing concern. A faster connection may make pages load or respond more quickly and feel more responsive, but is not required for effective home work scenarios. PAC, ARC, FDS, CUIT VPN, etc., do not require fast internet connections as they transmit very little data. Almost all processing is done on the server (e.g., Columbia) end of the connection -- slowness in ARC, for example, while validating budgets is not a function of one's internet speed. This is directly related to the complexity of the operations being performed on the ARC servers. Likewise, LionMail and Outlook transmit very little data and do not require fast connections.

  • Remote Desktop Connections to an on-campus PC do not have substantial bandwidth requirements, and these requirements are lower than those for Zoom. A stable Remote Desktop Connection to an on-campus PC can require as little as 200Kbps (not Mbps) upstream/downstream.


In-home WiFi Routers

  • If you lease/rent your WiFi router from your Internet Service Provider (ISP) -- It is very common for in-home routers to be leased from your ISP (Comcast, Spectrum, FiOS, etc.). In such cases, please contact your Internet Service Provider directly about issues with your in-home WiFi, as they often have remote management tools that allow them to assess the status of your home network remotely. If your equipment is misconfigured, or if there is an issue with your leased hardware, your ISP will be best positioned to assist you with fixing the issue or with replacing your equipment.
    • It can be a non-trivial procedure to use your own WiFI router in conjunction with the equipment provided by your ISP -- your first course of actions should be to contact the ISP right away with your connectivity questions and concerns. ISP WiFi routers typically combine the functionality of a modem (which communicates with the internet) and WiFi router (which communicates between your computer and the modem then, in turn, the internet), so you should consult with your ISP before purchasing your own equipment.
  • Consumer WiFi routers (which are purchased outright, rather than leased from an ISP) vary widely in quality. If you are experiencing slowness or instability in your connection, even when your computer is located close to the WiFi router itself, you may want to try rebooting your router. To do so, unplug the power cable from the router for 30 seconds then plug it back in and allow it to reboot.
  • If you wish to purchase a new WiFi router resolve home internet speeds, please first check with your ISP to verify that there are not issues on their end (rather than with your router). Please also use the above resources to check your actual current internet speeds -- different sites will perform differently based upon the network load, so Zoom slowness does not automatically imply that your connection is slow or unstable.
  • If you do determine that you need a new in-home WiFi router, please consider the below models. The first two are recommended by CUIT for on-campus housing (more information here), and the latter models are general recommendations for stable and high quality routers.
  • For installation of routers in CUIT-serviced locations, please contact CUIT for in-home or phone based support. For installation in off-campus housing, please consult the manufacturer's installation instructions.