Comcast download speed fix for Linksys eSeries - Revision history http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&action=history Revision history for this page on the wiki en MediaWiki 1.10.1 Thu, 28 Mar 2024 16:36:03 GMT Ian5142: Added Advanced tutorials category. http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=53948&oldid=prev <p>Added Advanced tutorials category.</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 18:15, 18 March 2018</td> </tr> <tr><td colspan="2" align="left"><strong>Line 53:</strong></td> <td colspan="2" align="left"><strong>Line 53:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Linksys guides]]</td><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Linksys guides]]</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Linksys]]</td><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Linksys]]</td></tr> <tr><td colspan="2">&nbsp;</td><td>+</td><td style="background: #cfc; font-size: smaller;">[[Category:Advanced tutorials]]</td></tr> </table> Sun, 18 Mar 2018 18:15:24 GMT Ian5142 http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries Ian5142: /* References */ http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=53166&oldid=prev <p><span class="autocomment">References</span></p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 17:47, 19 November 2017</td> </tr> <tr><td colspan="2" align="left"><strong>Line 51:</strong></td> <td colspan="2" align="left"><strong>Line 51:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Tutorials| ]]</td><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Tutorials| ]]</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Comcast| ]]</td><td> </td><td style="background: #eee; font-size: smaller;">[[Category:Comcast| ]]</td></tr> <tr><td colspan="2">&nbsp;</td><td>+</td><td style="background: #cfc; font-size: smaller;">[[Category:Linksys guides]]</td></tr> <tr><td colspan="2">&nbsp;</td><td>+</td><td style="background: #cfc; font-size: smaller;">[[Category:Linksys]]</td></tr> </table> Sun, 19 Nov 2017 17:47:34 GMT Ian5142 http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: clarify http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46092&oldid=prev <p>clarify</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 01:06, 25 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 5:</strong></td> <td colspan="2" align="left"><strong>Line 5:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">There is an edge case interaction between Comcast IPv4 [https://en.wikipedia.org/wiki/Differentiated_services DSCP] and improper condition handling in the [https://en.wikipedia.org/wiki/Wireless_Multimedia_Extensions WMM] driver in certain '''Linksys/Cisco eSeries''' routers (and possibly others as well) which results in very low download speeds. This issue can appear in both stock and third-party (DD-WRT) firmware, although Cisco appears to have at some point released new WMM drivers that largely resolve the issue in current stock firmware.</td><td> </td><td style="background: #eee; font-size: smaller;">There is an edge case interaction between Comcast IPv4 [https://en.wikipedia.org/wiki/Differentiated_services DSCP] and improper condition handling in the [https://en.wikipedia.org/wiki/Wireless_Multimedia_Extensions WMM] driver in certain '''Linksys/Cisco eSeries''' routers (and possibly others as well) which results in very low download speeds. This issue can appear in both stock and third-party (DD-WRT) firmware, although Cisco appears to have at some point released new WMM drivers that largely resolve the issue in current stock firmware.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">The cause is that IPv4 packets from the Comcast network are configured with DSCP 8, which the driver handles improperly, whereas other providers typically use DSCP 0. (Both are valid values.)</td><td>+</td><td style="background: #cfc; font-size: smaller;">The cause is that IPv4 packets from the Comcast network are configured with DSCP 8, which the driver handles improperly, whereas other providers typically use DSCP 0<ins style="color: red; font-weight: bold; text-decoration: none;">, which the driver handles properly</ins>. (Both are valid values.)</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> </table> Sat, 25 Jan 2014 01:06:52 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: clarify http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46091&oldid=prev <p>clarify</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 00:58, 25 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 38:</strong></td> <td colspan="2" align="left"><strong>Line 38:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">This fix changes DSCP header information in all packets to 0 when they arrive at the WAN interface of the router, which the WMM driver handles properly.</td><td>+</td><td style="background: #cfc; font-size: smaller;">This fix changes DSCP header information in all packets to <ins style="color: red; font-weight: bold; text-decoration: none;">DSCP </ins>0 when they arrive at the WAN interface of the router, which the WMM driver handles properly.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> </table> Sat, 25 Jan 2014 00:58:44 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: clarify http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46090&oldid=prev <p>clarify</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 00:57, 25 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 11:</strong></td> <td colspan="2" align="left"><strong>Line 11:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">Download speeds are normal with ''current'' stock firmware, and on ''wired'' connections with DD-WRT firmware, but are much lower (possibly even less than 1 Mbps) on ''wireless'' connections with DD-WRT firmware even with strong signal.</td><td> </td><td style="background: #eee; font-size: smaller;">Download speeds are normal with ''current'' stock firmware, and on ''wired'' connections with DD-WRT firmware, but are much lower (possibly even less than 1 Mbps) on ''wireless'' connections with DD-WRT firmware even with strong signal.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">To see if you are getting the problematic DSCP, look at your downloaded IPv4 packets with [http://www.wireshark.org/ Wireshark], preferably directly connected to WAN, but you should see them even on Wi-Fi. (See [http://netspoon.wordpress.com/2012/09/08/add-dscp-column-in-wireshark/ Add DSCP Column in Wireshark])</td><td>+</td><td style="background: #cfc; font-size: smaller;">To see if you are getting the problematic DSCP, <ins style="color: red; font-weight: bold; text-decoration: none;">you can </ins>look at your downloaded IPv4 packets with [http://www.wireshark.org/ Wireshark], preferably directly connected to WAN, but you should see them even on Wi-Fi. (See [http://netspoon.wordpress.com/2012/09/08/add-dscp-column-in-wireshark/ Add DSCP Column in Wireshark])</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> </table> Sat, 25 Jan 2014 00:57:39 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: clarify http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46089&oldid=prev <p>clarify</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 00:56, 25 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 5:</strong></td> <td colspan="2" align="left"><strong>Line 5:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">There is an edge case interaction between Comcast IPv4 [https://en.wikipedia.org/wiki/Differentiated_services DSCP] and improper condition handling in the [https://en.wikipedia.org/wiki/Wireless_Multimedia_Extensions WMM] driver in certain '''Linksys/Cisco eSeries''' routers (and possibly others as well) which results in very low download speeds. This issue can appear in both stock and third-party (DD-WRT) firmware, although Cisco appears to have at some point released new WMM drivers that largely resolve the issue in current stock firmware.</td><td> </td><td style="background: #eee; font-size: smaller;">There is an edge case interaction between Comcast IPv4 [https://en.wikipedia.org/wiki/Differentiated_services DSCP] and improper condition handling in the [https://en.wikipedia.org/wiki/Wireless_Multimedia_Extensions WMM] driver in certain '''Linksys/Cisco eSeries''' routers (and possibly others as well) which results in very low download speeds. This issue can appear in both stock and third-party (DD-WRT) firmware, although Cisco appears to have at some point released new WMM drivers that largely resolve the issue in current stock firmware.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">The cause is that IPv4 packets from the Comcast network are configured with DSCP 8, whereas other providers typically use DSCP 0.</td><td>+</td><td style="background: #cfc; font-size: smaller;">The cause is that IPv4 packets from the Comcast network are configured with DSCP 8<ins style="color: red; font-weight: bold; text-decoration: none;">, which the driver handles improperly</ins>, whereas other providers typically use DSCP 0. <ins style="color: red; font-weight: bold; text-decoration: none;">(Both are valid values.)</ins></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td colspan="2" align="left"><strong>Line 38:</strong></td> <td colspan="2" align="left"><strong>Line 38:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">This fix changes DSCP header information in all packets to 0 when they arrive at the WAN interface of the router, which the WMM driver <del style="color: red; font-weight: bold; text-decoration: none;">then </del>handles properly.</td><td>+</td><td style="background: #cfc; font-size: smaller;">This fix changes DSCP header information in all packets to 0 when they arrive at the WAN interface of the router, which the WMM driver handles properly.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> </table> Sat, 25 Jan 2014 00:56:49 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: clarify http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46088&oldid=prev <p>clarify</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 00:54, 25 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 38:</strong></td> <td colspan="2" align="left"><strong>Line 38:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">This fix changes DSCP header information <del style="color: red; font-weight: bold; text-decoration: none;">as soon as a packet hits </del>the WAN interface <del style="color: red; font-weight: bold; text-decoration: none;">on </del>the router<del style="color: red; font-weight: bold; text-decoration: none;">.</del></td><td>+</td><td style="background: #cfc; font-size: smaller;">This fix changes DSCP header information <ins style="color: red; font-weight: bold; text-decoration: none;">in all packets to 0 when they arrive at </ins>the WAN interface <ins style="color: red; font-weight: bold; text-decoration: none;">of </ins>the router, which the WMM driver <ins style="color: red; font-weight: bold; text-decoration: none;">then </ins>handles properly.</td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">&#160;</td><td>+</td><td style="background: #cfc; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;"><del style="color: red; font-weight: bold; text-decoration: none;">DSCP as received from Comcast's network is 8. This is actually higher than Default priority, but the WMM driver interprets it incorrectly.</del></td><td>+</td><td style="background: #cfc; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">&#160;</td><td>+</td><td style="background: #cfc; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;"><del style="color: red; font-weight: bold; text-decoration: none;">The fix changes DSCP on all packets to 0 (Default priority)</del>, which the WMM driver handles properly. <del style="color: red; font-weight: bold; text-decoration: none;">(This is how other ISPs set DSCP and is why the issue is specific to Comcast.)</del></td><td>+</td><td style="background: #cfc; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> </table> Sat, 25 Jan 2014 00:54:51 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: clarify http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46087&oldid=prev <p>clarify</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 00:50, 25 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 5:</strong></td> <td colspan="2" align="left"><strong>Line 5:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">There is an edge case interaction between Comcast IPv4 [https://en.wikipedia.org/wiki/Differentiated_services DSCP] and improper condition handling in the [https://en.wikipedia.org/wiki/Wireless_Multimedia_Extensions WMM] driver in certain '''Linksys/Cisco eSeries''' routers (and possibly others as well) which results in very low download speeds. This issue can appear in both stock and third-party (DD-WRT) firmware, although Cisco appears to have at some point released new WMM drivers that largely resolve the issue in current stock firmware.</td><td> </td><td style="background: #eee; font-size: smaller;">There is an edge case interaction between Comcast IPv4 [https://en.wikipedia.org/wiki/Differentiated_services DSCP] and improper condition handling in the [https://en.wikipedia.org/wiki/Wireless_Multimedia_Extensions WMM] driver in certain '''Linksys/Cisco eSeries''' routers (and possibly others as well) which results in very low download speeds. This issue can appear in both stock and third-party (DD-WRT) firmware, although Cisco appears to have at some point released new WMM drivers that largely resolve the issue in current stock firmware.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;"><del style="color: red; font-weight: bold; text-decoration: none;">Unlike other service providers, </del>IPv4 packets from the Comcast network are configured with DSCP 8, <del style="color: red; font-weight: bold; text-decoration: none;">Priority higher than Default/Routine (</del>0<del style="color: red; font-weight: bold; text-decoration: none;">)</del>.</td><td>+</td><td style="background: #cfc; font-size: smaller;"><ins style="color: red; font-weight: bold; text-decoration: none;">The cause is that </ins>IPv4 packets from the Comcast network are configured with DSCP 8, <ins style="color: red; font-weight: bold; text-decoration: none;">whereas other providers typically use DSCP </ins>0.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> </table> Sat, 25 Jan 2014 00:50:04 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: remove incorrect theory http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46084&oldid=prev <p>remove incorrect theory</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 17:07, 23 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 10:</strong></td> <td colspan="2" align="left"><strong>Line 10:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Symptoms ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Symptoms ==</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">Download speeds are normal with ''current'' stock firmware, and on ''wired'' connections with DD-WRT firmware, but are much lower (possibly even less than 1 Mbps) on ''wireless'' connections with DD-WRT firmware even with strong signal.</td><td> </td><td style="background: #eee; font-size: smaller;">Download speeds are normal with ''current'' stock firmware, and on ''wired'' connections with DD-WRT firmware, but are much lower (possibly even less than 1 Mbps) on ''wireless'' connections with DD-WRT firmware even with strong signal.</td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;"></td><td colspan="2">&nbsp;</td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">Because DSCP pertains to QoS, it's possible this problem might only exist ''when QoS is enabled'' (and go away when QoS is disabled), but this has not been confirmed.</td><td colspan="2">&nbsp;</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">To see if you are getting the problematic DSCP, look at your downloaded IPv4 packets with [http://www.wireshark.org/ Wireshark], preferably directly connected to WAN, but you should see them even on Wi-Fi. (See [http://netspoon.wordpress.com/2012/09/08/add-dscp-column-in-wireshark/ Add DSCP Column in Wireshark])</td><td> </td><td style="background: #eee; font-size: smaller;">To see if you are getting the problematic DSCP, look at your downloaded IPv4 packets with [http://www.wireshark.org/ Wireshark], preferably directly connected to WAN, but you should see them even on Wi-Fi. (See [http://netspoon.wordpress.com/2012/09/08/add-dscp-column-in-wireshark/ Add DSCP Column in Wireshark])</td></tr> </table> Thu, 23 Jan 2014 17:07:15 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries JNavas: edit and cleanup http://wiki.dd-wrt.com/wiki/index.php?title=Comcast_download_speed_fix_for_Linksys_eSeries&diff=46015&oldid=prev <p>edit and cleanup</p> <table border='0' width='98%' cellpadding='0' cellspacing='4' style="background-color: white;"> <tr> <td colspan='2' width='50%' align='center' style="background-color: white;">←Older revision</td> <td colspan='2' width='50%' align='center' style="background-color: white;">Revision as of 17:21, 10 January 2014</td> </tr> <tr><td colspan="2" align="left"><strong>Line 6:</strong></td> <td colspan="2" align="left"><strong>Line 6:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">Unlike other service providers, IPv4 packets from the Comcast network are configured with DSCP 8, Priority higher than Default/Routine (0).</td><td> </td><td style="background: #eee; font-size: smaller;">Unlike other service providers, IPv4 packets from the Comcast network are configured with DSCP 8, Priority higher than Default/Routine (0).</td></tr> <tr><td colspan="2">&nbsp;</td><td>+</td><td style="background: #cfc; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Symptoms ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Symptoms ==</td></tr> <tr><td colspan="2" align="left"><strong>Line 13:</strong></td> <td colspan="2" align="left"><strong>Line 14:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">To see if you are getting the problematic DSCP, look at your downloaded IPv4 packets with [http://www.wireshark.org/ Wireshark], preferably directly connected to WAN, but you should see them even on Wi-Fi. (See [http://netspoon.wordpress.com/2012/09/08/add-dscp-column-in-wireshark/ Add DSCP Column in Wireshark])</td><td> </td><td style="background: #eee; font-size: smaller;">To see if you are getting the problematic DSCP, look at your downloaded IPv4 packets with [http://www.wireshark.org/ Wireshark], preferably directly connected to WAN, but you should see them even on Wi-Fi. (See [http://netspoon.wordpress.com/2012/09/08/add-dscp-column-in-wireshark/ Add DSCP Column in Wireshark])</td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;"></td><td colspan="2">&nbsp;</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Testing ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Testing ==</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">To test this fix, open a Telnet or SSH connection to DD-WRT, and run the following commands (copy and <del style="color: red; font-weight: bold; text-decoration: none;">pasting </del>to avoid typos):</td><td>+</td><td style="background: #cfc; font-size: smaller;">To test this fix, open a Telnet or SSH connection to DD-WRT, and run the following commands (copy and <ins style="color: red; font-weight: bold; text-decoration: none;">paste </ins>to avoid typos):</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"> insmod xt_DSCP.ko</td><td> </td><td style="background: #eee; font-size: smaller;"> insmod xt_DSCP.ko</td></tr> <tr><td colspan="2" align="left"><strong>Line 25:</strong></td> <td colspan="2" align="left"><strong>Line 25:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">Assuming there are no errors, check download speed on wireless.</td><td> </td><td style="background: #eee; font-size: smaller;">Assuming there are no errors, check download speed on wireless.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">You may need to change ''vlan2'' depending on your particular setup.</td><td colspan="2">&nbsp;</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Configuration ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Configuration ==</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">To save the fix so it survives reboots, <del style="color: red; font-weight: bold; text-decoration: none;">first </del>navigate to ''Administration'' &gt; ''Commands''</td><td>+</td><td style="background: #cfc; font-size: smaller;">To save the fix so it survives reboots, navigate to ''Administration'' &gt; ''Commands''</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">In Command Shell, enter Commands:</td><td>+</td><td style="background: #cfc; font-size: smaller;">In Command Shell, enter Commands <ins style="color: red; font-weight: bold; text-decoration: none;">(copy and paste to avoid typos)</ins>:</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"> insmod xt_DSCP.ko</td><td> </td><td style="background: #eee; font-size: smaller;"> insmod xt_DSCP.ko</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">and click ''Save Startup''.</td><td> </td><td style="background: #eee; font-size: smaller;">and click ''Save Startup''.</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td>-</td><td style="background: #ffa; font-size: smaller;">In Command Shell, enter Commands:</td><td>+</td><td style="background: #cfc; font-size: smaller;">In Command Shell, enter Commands <ins style="color: red; font-weight: bold; text-decoration: none;">(copy and paste to avoid typos)</ins>:</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"> iptables -t mangle -A PREROUTING -i `nvram get wan_ifname` -j DSCP --set-dscp 0</td><td> </td><td style="background: #eee; font-size: smaller;"> iptables -t mangle -A PREROUTING -i `nvram get wan_ifname` -j DSCP --set-dscp 0</td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">and click ''Save Firewall''.</td><td> </td><td style="background: #eee; font-size: smaller;">and click ''Save Firewall''.</td></tr> <tr><td colspan="2">&nbsp;</td><td>+</td><td style="background: #cfc; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td><td> </td><td style="background: #eee; font-size: smaller;">== Methodology ==</td></tr> <tr><td colspan="2" align="left"><strong>Line 45:</strong></td> <td colspan="2" align="left"><strong>Line 45:</strong></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">The fix changes DSCP on all packets to 0 (Default priority), which the WMM driver handles properly. (This is how other ISPs set DSCP and is why the issue is specific to Comcast.)</td><td> </td><td style="background: #eee; font-size: smaller;">The fix changes DSCP on all packets to 0 (Default priority), which the WMM driver handles properly. (This is how other ISPs set DSCP and is why the issue is specific to Comcast.)</td></tr> <tr><td colspan="2">&nbsp;</td><td>+</td><td style="background: #cfc; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;"></td><td> </td><td style="background: #eee; font-size: smaller;"></td></tr> <tr><td> </td><td style="background: #eee; font-size: smaller;">== References ==</td><td> </td><td style="background: #eee; font-size: smaller;">== References ==</td></tr> </table> Fri, 10 Jan 2014 17:21:36 GMT JNavas http://wiki.dd-wrt.com/wiki/index.php/Talk:Comcast_download_speed_fix_for_Linksys_eSeries