Connectivity
Connectivity and managing Your Comcast Business network
Male IT Specialist Holds Laptop and Discusses Work with Female Server Technician. They're Standing in Data Center, Rack Server Cabinet is Open.
Dean
New Member

Internet connectivity is not stable in these couple days.

To whom it my concern, 

 

Our company's account # is (removed for account security). The internet connectivity is not stable and the speed is pretty slow. I just did the ping and trace route to google's DNS server (8.8.8.8). It seems the congestion is in Comcast's backbone side. Could you please help me to check it? Thank you.

 

Best regards, 

Dean

------------

 

Ping and traceroute results.jpg

0 Kudos
5 REPLIES 5
Trusted Forum Contributor

Re: Internet connectivity is not stable in these couple days.

Dean,

 

"The internet connectivity is not stable and the speed is pretty slow." is a general statement and needs specifics.  What exactly is "not stable"?  What is "pretty slow"?  Is this only for specific connections or for every connection?

 

Traceroute results are always interesting.  Traceroute uses tailored pings with increasing hop count for each query. Intermidiate responses come from routers along the path where the hop count expires. The last response comes from the target system. The significant conclusions from the results you posted include:

  

The intermediate hop data most likely indicates that the routers queried were too busy forwarding data packets to handle ICMP Echo requests promptly.  For example, hop 8 in your data shows more than 10 times the time that hop 15 (8.8.8.8) shows. 

 

Actual queries to a DNS server would be prioritized over ECHO requests - this means DNS responses are received faster than ping or traceroute responses from DNS servers.  Only a DNS query/response interaction can indicate what kind of DNS performance you are experiencing.  Bluntly, expecting ping or traceroute performance to indicate DNS performance is expecting the taste of an apple to tell you if the milk is sour. 

 

Finally, if you believe that your problems, whatever they are, are related to DNS, try using the Comcast-provided DNS servers, or OpenDNS servers, or whatever NameBench shows is the fastest server in its test.  Then tell us what you find out.

 

 

0 Kudos
Trusted Forum Contributor

Re: Internet connectivity is not stable in these couple days.

I'd like to add that while a traceroute it useful, it's only one sided. You'd need to see the outbound to be able to see what's really going on. There is a chance that your issue is on the outbound and your trace suggest sometype of maintenance taking place or a congested link/overloaded router. 

 

Definitely would like to see some more information on if the problem is specific to GoogleDNS or if this occurs everywhere. You should also post your modems signal levels for completeness. Those can be found by going to http://10.1.10.1/ and clicking on the "Cable modem" page. 

0 Kudos
JaseinatlAGAIN
Visitor

Re: Internet connectivity is not stable in these couple days.

What is the best way to prove that there are measurable spikes in service and connectivity using Comcast Business? I see them clearly in several applications, but I would like to know from the experts what would constitute irrefutable proof that Comcast Business Internet often becomes unresponsive. This happens from every PC on my network. This is not a modem or a router issue, this is a Comcast Business issue and once you tell me the correct tools to use, I will do so gladly. 

 

Thanks in advance for your help.

 

Jase

0 Kudos
Trusted Forum Contributor

Re: Internet connectivity is not stable in these couple days.


@JaseinatlAGAIN wrote:

What is the best way to prove that there are measurable spikes in service and connectivity using Comcast Business? I see them clearly in several applications, but I would like to know from the experts what would constitute irrefutable proof that Comcast Business Internet often becomes unresponsive. This happens from every PC on my network. This is not a modem or a router issue, this is a Comcast Business issue and once you tell me the correct tools to use, I will do so gladly. 

 

Thanks in advance for your help.

 

Jase



If you find the answer to that, do let us know...

 

On a serious note. Comcast should be willing to accept MTR/trace routes and other data but so far refuse. It's very important that they can see the issue in the act so that they can resolve it. Though, I'd recommend you continue taking data and saving it as you never know when it will become useful. 

 

@I've recently had luck with reaching out to @ComcastMike on Twitter. Been working with the Corporate ESL Escalation Team and they've been willing to accept my data. The good thing about them is they are your point of contact so you don't need to go back to square one each time you have another issue. 

0 Kudos
Highlighted
LeeThompson
New Contributor

Re: Internet connectivity is not stable in these couple days.

There are some handy tools for tracking down network issues.

 

Ookla's Speed Test is good for testing for throughput.

http://www.speedtest.net/

 

Berkeley's Netalyzer can be very useful for tracking down latency, DNS, config and other issues.  (It also does some speed testing but isn't as good as Ookla's).    Unfortunately it requries Java runtime.  (It's also available for Android for free.)

http://netalyzr.icsi.berkeley.edu/

 

DSL Reports has some tools, although not as good as they used to be.

http://www.dslreports.com/tools

 

 

Traceroutes have their uses (mostly for tracking down misconfigured edges or otherwise borked routing rules) but, as has been said, only show the connectivity route in one direction and you can get some bad data if there are firewalls or other network security measures involved.