{"id":504,"date":"2009-11-12T23:36:22","date_gmt":"2009-11-13T03:36:22","guid":{"rendered":"https:\/\/lowtek.ca\/roo\/?p=504"},"modified":"2023-11-24T14:03:45","modified_gmt":"2023-11-24T18:03:45","slug":"speedtouch-516-dsl-metrics","status":"publish","type":"post","link":"https:\/\/lowtek.ca\/roo\/2009\/speedtouch-516-dsl-metrics\/","title":{"rendered":"SpeedTouch 516 DSL metrics"},"content":{"rendered":"

\"network\"<\/a><\/p>\n

Like many folks my internet connection is connected to a router\/gateway.\u00a0 The router acts as the hub of my internal network providing both access to other machines on my local network as well as the internet.\u00a0 In my case I have a SpeedTouch 516 DSL modem<\/a>, plugged into a Linksys WRT54GL<\/a> router\/gateway, and an assortment of PCs plugged into the router.<\/p>\n

If you have a single PC, then it makes sense to plug your DSL modem directly into your computer.\u00a0 This has the advantage of making it easy to talk directly to your DSL modem for configuration (usually via a web interface on the modem itself).\u00a0 Some modems provide various statistics about your connection.\u00a0 There is also a tool called DMT<\/a> which gives you a nice graphical interface to the data.<\/p>\n

Now if your network is at all configured like mine, you can’t easily talk to the DSL modem since the router is in the way.\u00a0 Assuming you are running the alternate router firmware DD-WRT<\/a>, there is a solution that will expose your DSL modem to your network.<\/p>\n

You need to gather two bits of information about your DSL modem, and the easiest manner to do this is to plug it directly into a PC via an ethernet cable.\u00a0 The modem should act as a DHCP server and hand out an address to your PC.\u00a0 You want to collect both the IP (cilent) address that your PC was assigned, and the gateway address (the IP of the DSL modem).<\/p>\n

In my case I had:
\nclient IP address 192.168.1.64
\ngateway IP address 192.168.1.254<\/code><\/p>\n

Then we telnet to the DD-WRT enabled Linksys box (yup, telnet is always enabled for the local network).\u00a0 You log in using user root (even if you have changed the web interface user name) and the password you use for the web interface.<\/p>\n

We are going to temporarily modify the routers configuration with the following two commands:
\n\/sbin\/ifconfig vlan1:1 192.168.1.64 \\
\nnetmask 255.255.255.0<\/code><\/p>\n

\/usr\/sbin\/iptables -I POSTROUTING -t nat -o vlan1 \\
\n-d 192.168.1.0\/24 -j MASQUERADE<\/code><\/p>\n

If you want to make this more permanent, the DD-WRT wiki has some instructions<\/a> on how to do this along with a few more details as to what we’re doing in the commands above.\u00a0 Assuming all went well, we can now visit the DSL modem’s web interface at http:\/\/192.168.1.254 – do this to validate that you’ve got things working ok.<\/p>\n

Now we go grab a copy of DMT<\/a> (this is a windows only program).\u00a0 For the SpeedTouch 516 you want version 7.35.\u00a0 By running this on a windows PC connected to your network, you should get some data out of your DSL modem in a nice graphical form.<\/p>\n

\"dmt20091111_2249\"<\/a><\/p>\n

So neat-o, we’ve got some nice data here.\u00a0 What does it mean?\u00a0 A good reference can be found here<\/a> – let’s look at my results using that reference.\u00a0 The downstream attenuation of 48.0dB falls into the ‘good’ category, a lower value is better and much higher than 50 is not so good.\u00a0 The Signal to Noise Ratio Margin (SNRM) of 10.0dB rates as fair, with this value bigger is better – a result of 6dB or less would be very bad.\u00a0 The last area I’ll talk about is the upper right yellow box showing errors – ideally you want no errors, any\u00a0 increase in CRC errors after your initial connection is established is a problem and usually points to a physical issue somewhere between the modem and the telephone companies equipment.<\/p>\n

What if you don’t like Windows?\u00a0 You’re in luck – all of this data can be gathered via telnet.\u00a0 Simply telnet 192.168.1.254 and log into the modem:<\/p>\n

$telnet 192.168.1.254
\nTrying 192.168.1.254...
\nConnected to 192.168.1.254.
\nEscape character is '^]'.
\nUsername : Administrator
\nPassword :
\n<\/code><\/p>\n

{Administrator}=>adsl info
\nModemstate\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0 up
\nOperation Mode\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0 G.992.1 Annex A
\nChannel Mode\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0 fast
\nNumber of resets\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0 1<\/p>\n

Vendor\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Local\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Remote
\nCountry\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0f\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0f
\nVendor\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 TMMB\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ALCB
\nVendorSpecific\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 3c61\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0000
\nStandardRevisionNr\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 01<\/p>\n

Downstream\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Upstream
\nMargin\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 [dB]\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 10.0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 8.0
\nAttenuation\u00a0 [dB]\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 48.0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 29.0
\nOutputPower\u00a0 [dBm]\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 19.5\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 11.5<\/p>\n

Intrinsic\/Actual\u00a0 Bandwidth\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 %
\nUpstream\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 82
\nDownstream\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 78<\/p>\n

Available Bandwidth\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Cells\/s\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Kbit\/s
\nDownstream\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 11924\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 5056
\nUpstream\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1886\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 800<\/p>\n

Transfer statistics
\nErrors
\nReceived FEC\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\nReceived CRC\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 117
\nReceived HEC\u00a0\u00a0\u00a0 :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 22
\nTransmitted FEC :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\nTransmitted CRC :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\nTransmitted HEC :\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0<\/p>\n

Near end failures since reset
\nLoss of frame:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 failures
\nLoss of signal:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 failures
\nLoss of power:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 failures
\nErrored seconds:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 47 seconds
\nNear end failures last 15 minutes
\nLoss of frame:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 seconds
\nLoss of signal:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 seconds
\nLoss of power:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 seconds
\nErrored seconds:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 seconds
\nNear end failures current day
\nErrored seconds:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 47 seconds
\nNear end failures previous day
\nErrored seconds:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 seconds
\n{Administrator}=><\/p>\n

So in my case, I’ve got CRC errors happening at a low rate indicating there is possibly some physical problem (ie: wiring).\u00a0 This is probably what led to a rash of recent DSL disconnect problems that prompted me to investigate this far in terms of self diagnosing the problem (because who wants to sit on hold with your ISP all day?).<\/p>\n

So this is what the phone line connected to my DSL modem looks like:<\/p>\n

\"img_3076\"<\/a>Look suspicious?\u00a0 Ok, so I’ve been meaning to fix that for a while.<\/p>\n

I also started searching on potential firmware upgrades, and came across some data<\/a> that indicates that my current 6.1.9.6.0 revision may not be all that stable.\u00a0 I’ll have to tinker with that soon too.<\/p>\n

I need to share one more goof with you.\u00a0 Jenn told me today that her email wasn’t working.\u00a0 I looked on the server and all appeared to be well, and it turns out it was her Mac acting up – it couldn’t see the mail server anymore.\u00a0 I checked with nslookup and the name was resolving fine, but ping to the same machine failed to map the name.\u00a0 Strange, I thought it was specific to the Mac until I later tried my linux box and it failed too… Huh?\u00a0 Turns out that I had reboot my router last night to clear some of the settings, since the router acts as my local DNS server\/cache it had forgotten the email servers IP address.\u00a0 Renewing the IP address on the email server cause the DNS entry on the router to refresh and all was well again.\u00a0 The lesson?\u00a0 Remember your network topology.<\/p>\n","protected":false},"excerpt":{"rendered":"

Like many folks my internet connection is connected to a router\/gateway.\u00a0 The router acts as the hub of my internal network providing both access to other machines on my local network as well as the internet.\u00a0 In my case I have a SpeedTouch 516 DSL modem, plugged into a Linksys WRT54GL router\/gateway, and an assortment … Continue reading “SpeedTouch 516 DSL metrics”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-504","post","type-post","status-publish","format-standard","hentry","category-computing"],"_links":{"self":[{"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/posts\/504","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/comments?post=504"}],"version-history":[{"count":12,"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/posts\/504\/revisions"}],"predecessor-version":[{"id":2238,"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/posts\/504\/revisions\/2238"}],"wp:attachment":[{"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/media?parent=504"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/categories?post=504"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lowtek.ca\/roo\/wp-json\/wp\/v2\/tags?post=504"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}