Author Topic: Connection Problems - See Graph  (Read 442 times)

HaHa

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Connection Problems - See Graph
« on: April 10, 2000, 08:03:00 PM »
I've been having some big time connection issues in the last couple days.

----------------------------------------------------------------------------------------------
| Hop | Err | IP Address    | Node Name                         | Location             | ms  |
----------------------------------------------------------------------------------------------
| 0   |     | 24.226.20.54  | cgowave-20-54.cgocable.net        | *                    |     |
| 1   |     | 24.226.8.1    | cgowave-8-gw.cgocable.net         | ?(Canada)            | 2   |
| 2   |     | 10.66.0.9     | -                                 | ...                  | 17  |
| 3   | 1   | 24.226.1.1    | cgowave-busy-core.cgocable.net    | ?(Canada)            | 53  |
| 4   |     | 206.222.95.85 | -                                 | ?(Canada)            | 42  |
| 5   | 2   | 209.176.95.17 | atm9-0-037.CR-1.uschcg.savvis.net | -                    | 117 |
| 6   | 1   | 209.83.222.26 | atm8-0-045.CR-1.usdlls.savvis.net | -                    | 150 |
| 7   | 3   | 216.90.2.66   | applink-1.usdlls.savvis.net       | -                    | 158 |
| 8   | 1   | 216.91.192.19 | beta.hitechcreations.com          | ?Grapevine, TX 76051 | 166 |
----------------------------------------------------------------------------------------------


Dunno whats causing it, my cable company isn't all that great but the problem appears to be stemming at the savvis end.

Offline Torque

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Connection Problems - See Graph
« Reply #1 on: April 10, 2000, 08:57:00 PM »
savvis always chokes for me and alot of other people, now alt route is gone dunno what to say.

HaHa

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Connection Problems - See Graph
« Reply #2 on: April 11, 2000, 01:24:00 AM »
Another graph (2:30 EST - i.e. no traffic my end)

---------------------------------------------------------------------------------------------
| Hop | Err | IP Address    | Node Name                         | Location             | ms |
---------------------------------------------------------------------------------------------
| 0   |     | 24.226.20.54  | cgowave-20-54.cgocable.net        | *                    |    |
| 1   |     | 24.226.8.1    | cgowave-8-gw.cgocable.net         | ?(Canada)            | 2  |
| 2   | 1   | 10.66.0.9     | -                                 | ...                  | 8  |
| 3   |     | 24.226.1.1    | cgowave-busy-core.cgocable.net    | ?(Canada)            | 10 |
| 4   |     | 206.222.95.85 | -                                 | ?(Canada)            | 10 |
| 5   |     | 209.176.95.17 | atm9-0-037.CR-1.uschcg.savvis.net | -                    | 29 |
| 6   |     | 209.83.222.26 | atm8-0-045.CR-1.usdlls.savvis.net | -                    | 53 |
| 7   |     | 216.90.2.66   | applink-1.usdlls.savvis.net       | -                    | 59 |
| 8   |     | 216.91.192.19 | beta.hitechcreations.com          | ?Grapevine, TX 76051 | 67 |
---------------------------------------------------------------------------------------------

Here's the actual graph:

-----------------------------------------------
 ms | Graph      | Network                    |
-----------------------------------------------
 2  | x          | Cogeco Cable Solutions     |
 8  | x--        | (private use)              |
 10 | -x         | Cogeco Cable Solutions     |
 10 |  x         | Rogers Network Services    |
 29 |   x-       | SAVVIS Communications      |
 53 |      x-    | Savvis Communications Corp |
 59 |      -x-   | SAVVIS Communications      |
 67 |       x--- | Applink Corp               |
-----------------------------------------------

Of course this is 2:30 so it isn't as bad, but during the day the ping/packet loss/disconnect becomes pretty darn bad.

Offline Skuzzy

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Connection Problems - See Graph
« Reply #3 on: April 11, 2000, 09:23:00 AM »
Okay, a word about traceroute data.  When you do a traceroute, you are only seeing one half of the equation.
The path you see, from your end, may not have a thing to do with the path data will take back to you, for any given type of connection.

Case in point, I just traced back to your IP address and here is the path it takes from here.

Also note, packet loss in a traceroute is not the best gauge of actual data loss of a connection.  We and most providers do put a lower priority on ICMP (ping) and traceroute packets in the routers, favoring TCP packets.

The lack of knowing the path back to your connection, and if a router is being slow to respond because of lower protocol priority, makes it very difficult to trouble shoot performance issues with a connection to any point of the Internet.

Note, cable companies are notorious for having very poor peering arrangments with backbones.  They make every attempt to keep the data on thier own networks, and have oversold the connections they have to the Internet.

Also note, cable modems are a physically shared network.  When you have X number of homes all attempting to get/put data over a single coax, data collisions occur.  When a collision occurs, guess which data packet will win the battle?  The one that was generated physically closer to the switch/hub.  This is just the nature and design of the coax based ethernet network.

This can make DSL and ISDN more dependable for data delivery, as long as the ISP you are connecting to, has not oversold his/her network/Internet connections.

Overall, traceroutes are not very good indicators of network performance.  A ping is better as a ping takes both directions into account of the data path.
However, traceroutes are good for finding dead routers in the path and pings may not be very accurate, given the priority of the packets is usually low.

In the gaming environment, it is very difficult to determine where and why a packet may get lost, or if it gets lost at all.  They could be arriving out of order, due to collisions or timeouts, in the case of TCP packets or just dropped if they are UDP.

Is there a good answer?  I wih there was one.  The Internet is a very dynamic network, and statistically, it should not work as well as it does.

Our own network under goes change weekly, if not daily.  With over 7,000 ISP's in the US alone and all of them having to upgrade regularly, it is truly amazing there are not more hiccups, burps, and farts than there are.  

All that said, I hope someone finds it usefull.  Thank you for your time.

Tracing route to cgowave-20-54.cgocable.net [24.226.20.54]
over a maximum of 30 hops:

  1     2 ms     1 ms     1 ms  rt2.applink.net [216.91.192.44]
  2     7 ms     6 ms     5 ms  atm8-0-078.CR-1.usdlls.savvis.net [216.90.2.65]

  3    13 ms     7 ms    15 ms  Serial1-0-1.GW1.DFW1.ALTER.NET [157.130.128.53]

  4    15 ms     7 ms     6 ms  103.ATM3-0.XR1.DFW4.ALTER.NET [146.188.240.42]
  5    15 ms    20 ms     8 ms  195.at-2-0-0.TR1.DFW9.ALTER.NET [152.63.98.242]

  6    48 ms    48 ms    48 ms  128.ATM6-0.TR1.TOR2.ALTER.NET [152.63.7.62]
  7    67 ms    70 ms    66 ms  199.ATM7-0.XR1.TOR2.ALTER.NET [152.63.128.37]
  8    49 ms    49 ms    56 ms  500.atm10/0/0.bb1.ham1.uunet.ca [152.63.129.101]

  9    51 ms    52 ms    51 ms  216.94.254.158
 10    52 ms    48 ms    50 ms  cgowave-0-49.cgocable.net [24.226.0.49]
 11    53 ms    59 ms    54 ms  bb1-fe0-0-0-100bt.busy1.on.home.net [24.226.1.51
]
 12    57 ms    57 ms    59 ms  10.66.0.10
 13    61 ms    60 ms    60 ms  cgowave-20-54.cgocable.net [24.226.20.54]

Trace complete.


------------------
Roy "Skuzzy" Neese
President, AppLink Corp.
http://www.applink.net
skuzzy@applink.net
Roy "Skuzzy" Neese
support@hitechcreations.com

Offline Saintaw

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Connection Problems - See Graph
« Reply #4 on: April 11, 2000, 09:42:00 AM »
Amen Skuzzy !

OMW to find a tracer that uses http / udp packets  
Saw
Dirty, nasty furriner.

HaHa

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Connection Problems - See Graph
« Reply #5 on: April 11, 2000, 10:04:00 PM »
I may be mistaken but I thought traceroute used ping.

i.e. When you do a ping to an ip the packets traverse the network and then come back, with traceroute you restrict the number of hops, e.g. (first hop: set max hops to 1, ping destination ip), (second hop: set max hops to 2, ping destination ip) etc.. I can look it up in my network book but I'm pretty sure that's how it works.

Here's another graph I just took today at 11pm:

----------------------------------------------------------------------------------------------
| Hop | Err | IP Address    | Node Name                         | Location             | ms  |
----------------------------------------------------------------------------------------------
| 0   |     | 24.226.20.54  | cgowave-20-54.cgocable.net        | *                    |     |
| 1   |     | 24.226.8.1    | cgowave-8-gw.cgocable.net         | ?(Canada)            | 2   |
| 2   | 1   | 10.66.0.9     | bb1-fe4-1-0.busy1.on.home.net     | ?---                 | 10  |
| 3   | 1   | 24.226.1.1    | cgowave-busy-core.cgocable.net    | ?(Canada)            | 13  |
| 4   | 1   | 206.222.95.85 | -                                 | ?(Canada)            | 14  |
| 5   |     | 209.176.95.17 | atm9-0-037.CR-1.uschcg.savvis.net | -                    | 179 |
| 6   | 1   | 209.83.222.26 | atm8-0-045.CR-1.usdlls.savvis.net | -                    | 200 |
| 7   |     | 216.90.2.66   | applink-1.usdlls.savvis.net       | -                    | 227 |
| 8   |     | 216.91.192.19 | beta.hitechcreations.com          | ?Grapevine, TX 76051 | 243 |
----------------------------------------------------------------------------------------------


Note that I'm using "visualroute", it does an average value per hop (over 20 tries I believe).

I do agree that cable companies tend to really.. uhm.. suck. In fact my company is having some severe issues right now. What I'm curious about is whether that 14->179 jump is me or savvis. After pinging a couple of other servers, I see the same jump so I suspect it's probably me.

Yeesh $40 a month for this cable modem garbage - "caveat emptor" everyone.

Offline Skuzzy

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Connection Problems - See Graph
« Reply #6 on: April 12, 2000, 05:50:00 AM »
First, traceroute programs do not use ping.  Ping uses the ECHO ICMP message for its purposes.

Traceroute programs are rather odd programs.  They actually make use of a hole in the network specs.

My point about the traceroutes is, due to the way it works, they only show one of the data paths and that is the path fromthe origination point.

In an actual connection from point A to point B on the Internet, the data paths between the two points are quite typically very different.

So you could do a traceroute and see absolutely nothing wrong, but still have packet loss and sporatic response times for data.

Games are pretty unique programs.  All Internet ready games require packets to be sent in a specific order.  This specific requirement leads to what a lot of people think are lost packets, when in fact the packets may have arrived out of order, due to collisions at some router or switch.

Now, lets talk about that gateway connection Savvis has with the cable network.  You noted the very different path the traceroute took from here to your connection.  Not even the same gateway router was used.
This is quite normal for cable modem companies.  In order to keep costs low, cable companies use two connections for each gateway to the Internet backbone providers.  One of the connections (which may be made up of multiple physical connections) is used for download traffic, or traffic back to your computer, and the other connection is used for upload traffic, or traffic coming from your computer destined for the Internet.

The connections the cable companies use for traffic destined for their network is usually pretty large, but the connection to supply data from their network to the Internet is usually pretty small.  A ratio of 90/10 is a pretty good assumption.

This keeps the cable modem companies costs under control as most data for most Internet users is destined for their computer and not the other way around.

Another way the cable modem companies cut costs is by using a floating connection(s) to the backbone providers.  In this scenario, which most cable companies use, they pay for average utilization with the speed of the connections floating between a specific high and low point.  These "on-demand" connections are cheaper, but at the expense of some data loss occurring during the time of the transition in speeds.

Now, who is responsible for what?  The cable company is responsible for the gateway into any backbone provider.

In your traceroute, it appears the pipe for data coming from the cable network is pretty small and possibly congested, which can, and usually does, cause UDP packets to get lost as TCP packets get higher priority through the Internet.

For games, TCP packets are not prefereable, unless the data is very critical.  TCP packets take longer to process as they require an ACK for each packet delivered.  UDP packets do not require and ACK, and for the most part are pretty reliable, unless they happen to traverse a congested router or switch.

Bottomline; if all providers did their jobs correctly, the pipes would hardly ever be overloaded and all Internet games would just work flawlessly.  For the most part, this is pretty true, cable companies and AOL are pretty unique in this aspect.

I hope this is helpful.


------------------
Roy "Skuzzy" Neese
President, AppLink Corp.
http://www.applink.net
skuzzy@applink.net
Roy "Skuzzy" Neese
support@hitechcreations.com