to continous ping in windows run command add the -t to the string
ping 192.168.1.1 -t
for other options in the run command enter cmd
then when the dos window opens enter
ping /help
73...bruce
On 3/31/2016 8:40 AM, Bill Crowell via BVARC wrote:
Hi All,
I’m writing this note in the hope that it will help other hams not
have to waste hours with the level 1 support people over this issue.
Yesterday, my connection was dropping more than usual. I was losing
data. And, for those who don’t know me, I’m very competent in the ways
of networking.
We all go to some site like speedtest.net to see what our speed is. I
have the Xfinity BLAST service that gives me up to 125Mbps downstream.
That doesn’t tell the whole story. The upstream speed and reliability
are just as important. This is because the protocols used for most
traffic are TCP and the link layer is wanting an ACK packet (among
others.) If the ACK packet is not received, the link retries. And,
when things get bad, the entire channel is spending all of its time
thrashing.
To test link integrity, I started running a ping to my server in
Dallas. You can do this on Mac or Linux rather easily. Windows ping
gives you only 4 pings by default. I’m sure that someone who is a
Windows person will give the appropriate syntax for a continuous ping.
You can ping a DNS server at 4.2.2.1.
So, start a ping to a target computer somewhere. THEN do the speed
test. If you see “request timed out”, you’re having an upstream issue.
Now to my equipment. I’m running a Motorola 6141 cable modem. This has
been the very best modem for a long time. I don’t pay Comcast for
their piece of junk. The modem connects to a Juniper SSG5 firewall and
then to my network. This is a DOCSIS 3.0 modem. What this means is
that it gets configuration settings from Comcast. These settings
include which channels to bond for the downstream and upstream
connections._What I had not realized is that the network sets the
TRANSMIT power levels of the modem._
During the protocol negotiation and then periodically, the ISP’s gear
will tell the modem to increase or decrease power. If the receive
signal strength is too low, Comcast will tell my modem to “QRO old man”.
You can see the RF side on the Signal page of the modem. This is the
Motorola:
I’ve got one, measly channel and the modem is just below it’s absolute
maximum power of 57dBmV!!!! Yesterday, it was at 57 dBmV all day. This
is when packets are definitely lost.
The downstream channels are all fine at 0 dBmV – parity.
Now, how to correct this. Ideally, Comcast would deal with the RF link
between the modem and their gear. They’re sending someone next week.
They’ll likely say that the splitter should be removed, but then I
have to choose between TV and Internet. You know the drill.
For those of you not paying attention, the whole system is digital and
this issue manifests itself with the digital TV as well.
What is needed is to even out the TX/RX levels. I’m not expecting the
$15/hour tech to understand this. So, I’m getting an amplifier
designed for this purpose. The key here is “active return”. That’s the
part where the amp boosts the upstream signal from the cable modem.
The splitter is being replaced with this:
https://www.amazon.com/gp/product/B003T2SLIO/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
I’m expecting the TX power to be a more reasonable 30-40 dBmV and the
problems to disappear.
73!
Bill
Bill Crowell, N4HPG
Pearland, TX
Text messaging one-handed since 1982
_______________________________________________
BVARC mailing list
[email protected]
http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
--
Bruce Paige, KK5DO
AMSAT Director Contests and Awards
AMSAT Board Alternate 2015-2016
ARRL Awards Field Checker (WAS, 5BWAS, VUCC), VE
Houston AMSAT Net - Wed 0100z on Echolink - Conference *AMSAT*
Also live streaming MP3 at http://www.amsatnet.com
Podcast at http://www.amsatnet.com/podcast.xml or iTunes
Latest satellite news on the ARRL Audio News
http://www.arrl.org
AMSAT on Twitter http://www.twitter.com/amsat
_______________________________________________
BVARC mailing list
[email protected]
http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
