Motorola Surfboard SBG6580’s QoS settings is actually hidden under Wireless > WMM section. However, different compared to some of the routers that already have different setup configurations. You can actually change each of QoS priority settings in SBG6580. However, great freedom comes at a cost, wrong setups can cause your wireless to have serious issues that are hard to diagnose and fix.

Please note that this section have the potential to make your wireless network unuseable, especially if you have multiple Access Points (AP) in your network. However, if you only have 1 single SBG6580 in your house, these setting changes should improve your wifi performance. Consider to have wired connection ready in case our recommendations break your Wireless network completely. We have provided default settings here as well, so that you can have a QoS setting to fall back on in case our recommendations break yours.

For the purpose of this SBG6580 QoS WMM guide. We will provide a screen shot detailing the potential changes that you can make to make your online experience smoother. Then we will give a little background at the end of this post to help you understand more about the QoS parameters.

Default WMM QoS Settings
Below is a screen shot of the default configuration in case you ever need to fall back.

SBG6580 QoS  Default Parameter

Changed WMM QoS Settings
SBG6580 QoS  Updated Parameter

Changes:
1. EDCA AP Parameter: AC_BE CWmax from 63 to 31.
2. EDCA AP Parameter: AC_BK CWmax from 1023 to 63.
3. EDCA STA Parameter: AC_BE CWmax from 1023 to 63.
4. EDCA STA Parameter: AC_BK CWmax from 1023 to 63.
5. Turn on the Discard rule.

SBG6580 WMM QoS Upper Section Configuration

The upper sections for your SBG6580 WMM (QoS) are typically pretty safe to change. Please read our generic WMM settings guide for more information on this part.

WMM Support: On
No-Acknowledgement: On
Power Save Support: Off

SBG6580 WMM QoS Lower Section Configuration

For the QoS parameters to actually take effect in this section, you need to enable WMM settings on the upper section.

Different Type of QoS Data Queues

AC_BE: Data 0 (Best Effort, BE): Medium priority queue, medium throughput and
delay. Most traditional IP data.
AC_BK: Data 1 (Background, BK): Lowest priority queue, high throughput. Bulk
data (Like FTP) that requires maximum throughput and is not time-sensitive.
AC_VI: Data 2 (Video, VI): High priority queue, minimum delay. Time-sensitive
data such as Video and other streaming media.
AC_VO: Data 3 (Voice, VO): Highest priority queue, minimum delay.
Time-sensitive data such as Voice over IP (VoIP).

Random Backoff and Minimum (CWmin) / Maximum (CWmax) Contention Windows

If an access point detects that the medium is in use (busy), it uses the DCF random backoff timer to determine the amount of time to wait before attempting to access a given channel again. Each access point
waits some random period of time between retries.

The wait time is initial a value within a range between Minimum Contention Window and Maximum Contention Window. CWmin to CWmax. The values that you can input is 2^n – 1. For example, you can input 3, 7, 15, 31, 63, 127, …, 1023, and so on.

When you have higher numbers of users, your network gains from having a higher number of waiting time window. Because it lowers the amount of wireless collisions which reduce retransmissions. However, if you have a small network having a high value can slow down your potential speed.

In general, you still want to have a lower value for Video and VO’s because you do want higher priority for those services.

AIFSN

The Arbitration Inter-Frame Spacing (AIFs) specifies a wait time (in milliseconds) for data frames. 802.11e uses interframe spaces to regulate which frames get access to available channels and to coordinate wait times for transmission of different types of data. The AIFs ensures that multiple access points do not try sending data at the same time but instead wait until a channel is free.

Valid values for AIFs are 1 through 255. You want to keep this value as low as you can, especially if you have a small network.

For our purposes, keep the setting as the original.

Transmission Opportunity TXOP

The Transmission Opportunity (TXOP) is an interval of time when a WMM client station has the right to initiate transmissions onto the wireless medium.

This value specifies (in milliseconds) the Transmission Opportunity (TXOP) for client stations; that is, the interval of time when a WMM client station has the right to initiate transmissions on the wireless network.

For our purposes, keep the setting as the original.


Comments

WMM Settings (QoS) | SBG6580 — 13 Comments

  1. Good technical info, thanks. A couple of issues:

    1) Upper configuration, the defaults are On/Off/On, not On/On/Off as you document them. Would be nice to have more detail about those settings.

    2) You advise changes to the Discard rules but these are not described.

  2. Just hooked up the Motorola SBG6580 and want to prioritize one Ethernet port for my magic jack so that I can reduce Latency and Jitter as much as possible if I am using torrent software, or downloading/uploading etc. Your guide is all about the wireless throughput but I need to just prioritize the one Ethernet port over all other connections. Can you please assist with settings or screenshots for this type of configuration?

  3. Thank you sooooooo much!!!! I have been fighting this piece of crap for a year plus or minus. I thought I had purchased the best thing on the market and the wireless was useless! It made no sense to me that my upload would be over double my download. I spent way too much time talking with the “help” line at motorola, changing the channels over and over or this setting or that because “I must have interference from other wireless in the area”. They were almost mocking and making me feel like it was all my fault and that there was nothing wrong with the modem. I used the setting you gave and all is well!! I cannot thank you enough!
    Maybe you should contact Motorola and offer troubleshooting lessons to all of their supposedly skilled help staff!!!

  4. The pictures for the QoS settings to be changed do not match the text just below them. Specifically,
    EDCA STA Parameter: AC_BE CWmax
    the pic says to change it from 1023 to 31 but the text below says 1023 to 63. Not sure which is right but wanted to point it out.

  5. Also experiencing the same/similar issue(s) and would liek to be able to prioritize a specific LAN port the modem, rather than continuing to compete with my roommate for bandwidth while he is constantly running uTorrent 24/7. Thanks, in advance, for any help you may be able to offer.

  6. I made these changes and when I run the speed test on http://www.dslreports.com/speedtest I still have large bufferbloat. Any ideas?

    I have Comcast Xfinity Blast and I usually get 87-90 mbps on all speed test sites. I am just trying to figure out this bufferbloat stuff.

    • It will come down to your QoS, and if the firmware in your router has an intelligent enough algorithm for handling the queues for all packets you’re sending. Some routers – like this one – will always have a bufferbloat problem, because you won’t be able to handle the firmware yourself.

      If changing to a wired connection doesn’t help, bridging a new and smarter router will definitely do it. You can find recommendations for routers online.

  7. I have 8 IP Cameras with PTZ capabilities. I have set up Static IPS for them and have done the Port Forwarding. MOst of the time he cameras cannot be accessed. When I loook for the in the SBG-6900-ac setup DHCO clients it says they are inactive. then some of them have ipv6 ip addresses. WHen I reset the cameras and plug them into an ivp4 port they are accessible on WAN and LAN. I went under this screen you show here and just turned them on and it seemed to make some accessible. But for the last 2 weeks I haven not been able to access all the cameras all the time. Seems like a $200 waste of money but I have faith. what do I change so nothing ever goers to sleep or take a brake exct?

    • Statically assigned ips’s will never show up on a dhcp table, but they will show up on an Arp scan
      On this router you can reserve addresses, but I would recommend you just leave ip cameras statically assigned outside the dhcp ip pool

      For a home use, 200 ips should be more than plenty

      I’m weird cuz I only leave dhcp address for wlan clients and everything wired gets a static ip

Leave a Reply

Your email address will not be published.