Clearwire/Clear for branch office connectivity?

Jason Roysdon - NANOG nanog.20110127 at jason.roysdon.net
Thu Jan 27 18:03:40 CST 2011


As a Clear customer, some things that I would inform you of:

Using RFC1918 in their backbone:

Traceroute from my internal network out:
$ traceroute 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 40 byte packets
 1  10.12.250.49 (10.12.250.49)  1.671 ms  1.467 ms  3.214 ms - my network
 2  10.12.249.1 (10.12.249.1)  15.594 ms  15.530 ms  17.015 ms - my network
 3  192.168.15.1 (192.168.15.1)  17.957 ms  17.882 ms  18.978 ms - Clear CPE router device
 4  * * *
 5  10.41.229.197 (10.41.229.197)  82.081 ms  83.805 ms  52.455 ms
 6   (71.22.8.161)  72.237 ms  72.105 ms  73.546 ms
 7   (71.22.8.253)  75.988 ms  75.915 ms  76.095 ms
 8  xe-10-3-0.bar1.SanFrancisco1.Level3.net (4.53.132.13)  73.130 ms  75.894 ms  75.801 ms
 9  ae-0-11.bar2.SanFrancisco1.Level3.net (4.69.140.146)  79.860 ms  79.785 ms  76.723 ms
10  ae-6-6.ebr2.SanJose1.Level3.net (4.69.140.154)  79.558 ms  86.145 ms  86.056 ms
11  ae-92-92.csw4.SanJose1.Level3.net (4.69.134.222)  88.848 ms
ae-72-72.csw2.SanJose1.Level3.net (4.69.134.214)  79.919 ms
ae-92-92.csw4.SanJose1.Level3.net (4.69.134.222)  87.548 ms
12  ae-2-79.edge2.SanJose1.Level3.net (4.68.18.79)  77.322 ms
ae-1-69.edge2.SanJose1.Level3.net (4.68.18.15)  78.785 ms
ae-4-99.edge2.SanJose1.Level3.net (4.68.18.207)  77.568 ms
13  YOU-TUBE-IN.edge2.SanJose1.Level3.net (4.79.40.178)  80.985 ms  79.992 ms  81.634 ms
14  72.14.232.138 (72.14.232.138)  77.333 ms 72.14.232.136 (72.14.232.136)  81.425 ms
72.14.232.138 (72.14.232.138)  81.579 ms
15  216.239.47.186 (216.239.47.186)  102.799 ms 216.239.49.198 (216.239.49.198)  98.672
ms  107.898 ms
16  216.239.43.228 (216.239.43.228)  99.203 ms  99.134 ms  101.426 ms
17  216.239.48.165 (216.239.48.165)  101.391 ms 216.239.48.137 (216.239.48.137)  101.234
ms 216.239.48.165 (216.239.48.165)  110.738 ms
18  209.85.254.150 (209.85.254.150)  103.835 ms  104.921 ms 209.85.254.146
(209.85.254.146)  110.847 ms
19  google-public-dns-a.google.com (8.8.8.8)  90.106 ms  97.549 ms  93.919 ms

Hops 1-3 are mine.  Hops 4-7 is Clear's backbone.

Clear doesn't use PTR records all the time, see hops 6 & 7.

Traceroute back to my Clear IP on my CPE router device:
$ traceroute (address removed)
traceroute to (address removed), 30 hops max, 60 byte packets
 1  removed 1.812 ms  2.173 ms  2.087 ms
 2  public IP, removed  2.731 ms  2.635 ms  2.591 ms
 3  public IP, removed  2.549 ms  2.520 ms  2.467 ms
 4  0.ge-2-0-1.xt1.sac1.alter.net (152.63.51.81)  5.194 ms  5.170 ms  5.384 ms
 5  0.so-5-2-0.xl3.sjc7.alter.net (152.63.48.6)  50.991 ms  49.159 ms  49.088 ms
 6  0.ae3.br1.sjc7.alter.net (152.63.51.38)  9.644 ms 0.ae3.br3.sjc7.alter.net
(152.63.50.5)  9.394 ms  9.352 ms
 7  xe-9-2-0.edge1.sanjose3.level3.net (4.68.62.109)  10.201 ms  10.146 ms  10.107 ms
 8  vlan69.csw1.sanjose1.level3.net (4.68.18.62)  18.609 ms
vlan99.csw4.SanJose1.Level3.net (4.68.18.254)  13.095 ms vlan89.csw3.SanJose1.Level3.net
(4.68.18.190)  12.120 ms
 9  ae-82-82.ebr2.sanjose1.level3.net (4.69.134.217)  10.507 ms
ae-62-62.ebr2.sanjose1.level3.net (4.69.134.209)  9.397 ms  9.344 ms
10  ae-1-6.bar2.sanfrancisco1.level3.net (4.69.140.153)  10.429 ms  9.605 ms  9.767 ms
11  ae-0-11.bar1.sanfrancisco1.level3.net (4.69.140.145)  9.741 ms  10.291 ms  10.172 ms
12  clearwire-c.bar1.sanfrancisco1.level3.net (4.53.132.14)  11.604 ms  11.598 ms  11.523 ms
13  71.22.8.254 (71.22.8.254)  10.122 ms  10.046 ms  10.038 ms
14  71.22.8.162 (71.22.8.162)  12.713 ms  10.839 ms  11.142 ms
15  * * *
16  * * *
17  * * *

Traceroute back to my Clear CPE router's default gateway:
$ traceroute 50.8.128.1
traceroute to 50.8.128.1 (50.8.128.1), 30 hops max, 60 byte packets
 1  removed 1.812 ms  2.173 ms  2.087 ms
 2  public IP, removed  2.731 ms  2.635 ms  2.591 ms
 3  public IP, removed  2.549 ms  2.520 ms  2.467 ms
 4  0.ge-2-0-1.xt1.sac1.alter.net (152.63.51.81)  21.532 ms  21.529 ms  21.510 ms
 5  0.so-5-2-0.xl3.sjc7.alter.net (152.63.48.6)  30.556 ms  32.337 ms  32.309 ms
 6  0.ae3.br1.sjc7.alter.net (152.63.51.38)  32.298 ms 0.ae3.br3.sjc7.alter.net
(152.63.50.5)  38.977 ms 0.ae3.br1.sjc7.alter.net (152.63.51.38)  40.915 ms
 7  xe-8-1-0.edge1.sanjose3.level3.net (4.68.110.249)  27.102 ms  13.003 ms  21.180 ms
 8  vlan79.csw2.SanJose1.Level3.net (4.68.18.126)  21.157 ms  18.735 ms
vlan89.csw3.sanjose1.level3.net (4.68.18.190)  29.614 ms
 9  ae-62-62.ebr2.sanjose1.level3.net (4.69.134.209)  29.598 ms  22.253 ms
ae-72-72.ebr2.SanJose1.Level3.net (4.69.134.213)  34.313 ms
10  ae-1-6.bar2.sanfrancisco1.level3.net (4.69.140.153)  22.176 ms  22.859 ms  27.192 ms
11  ae-0-11.bar1.sanfrancisco1.level3.net (4.69.140.145)  27.140 ms  25.919 ms  25.114 ms
12  clearwire-c.bar1.sanfrancisco1.level3.net (4.53.132.14)  26.566 ms  26.525 ms  26.465 ms
13  71.22.8.254 (71.22.8.254)  24.857 ms  26.655 ms  26.201 ms
14  71.22.8.162 (71.22.8.162)  15.488 ms  17.219 ms  17.212 ms
15  50-8-128-1.sfo.clearwire-wmx.net (50.8.128.1)  17.194 ms  11.126 ms  11.075 ms

Clear's new WiMax routers do not allow you to bridge or use your public IP address
directly.  They force the router to NAT.  However, you can turn off all firewalling and
do a one-to-one NAT to a single device (as I've done to my Linux router).  It does pass
protocols such as 41 (for IPv6 tunneling over IPv4).  You can get a "static" IP on the
CPE router by paying more (something in the range of $5 or $10/month).  I've not had my
non-static IP change yet (Using dynamic dns to remote back in).

Think of Clear's tech support as lower than your home DSL provider's support levels. 
About all they can do is have you reboot your computer and reset your CPE router.

Examples of less-than-helpful tech support:
"If you log into your router - we don't support that and you cannot make any changes"
(this is requires for the above disabling of their firewall and one-to-one NAT setup
which is totally unsupported - or just to see the exact signal strength or get the MAC
address to report to them so you don't have to move the device).

"Our router is not grounded, so you must plug it directly into the [mains] otherwise it
builds up static" (in response that it is never a power loss that has caused me
problems, as I have it on a surge-protecting UPS with my home Linux router which never
has a problem).

Having to manually aim your CPE router means you'd want to have a professional do it and
make sure it is not going to move.  There are a number of places that sell outside
mounting/housing equipment so you can aim and get the best signal.

This is a low-end solution for low-end costs (think MetroPCS/Cricket from the
pay-as-you-go cell phone market - except with a 2 year contract).  I think it's a good
backup solution for the SOHO because sometimes DSL/Cable does have issues, but I would
not use it for a business primary solution.

I'd been a relatively happy customer of Clear for the last year for the price ($29/mo) I
pay.  My experience of the last week is not so happy.  I have a direct line of sight to
their tower from my two story house (once you get through one sheet of drywall and the
roof).  Their tower is less than a mile away and I have 4-5 bars of service.  Suddenly
my service was horrible this last week, with constant loss of Internet access.  Ping
monitoring to their default gateway will continue to work, but not beyond.  Ping
monitoring to their default gateway from co-located hosts doesn't have problems at this
time.  Resetting CPE router device fixes it, but problems can resume within as little as
20 minutes.

Current solution which has worked for the last 24 hours was to use their online map to
find the next best tower:  I have repositioned the CPE router to point at a different
tower and now that tower is the only one my CPE router detects (previously my CPE router
could see 3-4 towers as there are a few a few more miles away to the left and right of
the tower I was using).  Again I get a consistent 4-5 bars with this other tower, but
now no more problems.

My guess is that there is some sort of malfunction at the other tower.  Originally I
thought my CPE router was having a problem (which is leased from Clear and they were
sending a new one, not to arrive for another 3-4 days), as the problem would not fix
itself without resetting the CPE router and was instantly fixed after resetting it. 
However, as of now I've had 24+ hours without problems so I believe the problem is with
the tower or was with Clear's network and not the CPE router (the CPE router had been
getting reset 10+ times per day as the household has been having issues the last 7 days,
and the only change yesterday was pointing to a new tower and not a power cycle).

Check their online maps, service is very spotting with many holes.  My residence shows
as not getting service (showing signal is blocked 2-3 blocks away by other buildings),
but as I have a two story and have it mounted at the top of my house it has a clear line
of sight.  Look at their support pages on how they say to move it all around your house
to find the best room to install it in for signal.  According to their support site,
don't install it too close to anything (Wifi, or any other electrical device) as that
will block service as well (this is not true as far as I have observed while monitoring
signal strength with numbers from the CPE device).

I'd never consider using their mobile service as it would be so unreliable as to where
you could get service.  They tried to get my local PD to switch from AT&T's wireless
data service in the cars to Clear a few years back and the trails were so bad and
spotty.  I'd never consider using their VoIP service (even if it was free) as their
latency jitter just doesn't cut it.

Jason Roysdon

> Since I'm not with Clearwire anymore (end of contract) I can say that
> there are people in the core networking that do follow and respond the
> this list.
> 
> I can say that their backbone is solid and the people there really do
> care about the network.
> 
> If you have serious a backbone issue with Clearwire a message on this
> list will result in a response..
> 
> --
> Joe Hamelin, W7COM, Tulalip, WA, 360-474-7474





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