First hop on all tracert...

[R. J. Salvi]

...is this:

10.69.128.1

Anyone know why? Thx.

[Darren New]

Post by R. J. Salvi
10.69.128.1
Anyone know why? Thx.

That's your modem.

[Sal Bompensaro]

Post by Darren New

Post by R. J. Salvi
10.69.128.1
Anyone know why? Thx.

That's your modem.

My first hop is always 10.71.0.1.

I don't think it's the modem though. If it were a device on my LAN, the
ping time would be less than 1ms. Instead, it's around 6-10ms. I'm thinking
it's the first gateway that I encounter at Roadrunner.

When you have standard residential-class service, the modem TW gives you
seems to act as nothing more than a "bridge." It doesn't appear to have it's
own address. I noticed, however, that when I had business-class service, I
received a more sophisticated cable modem. That modem had its own IP address
and acted as a router instead of a bridge. In that case, the modem was
always the first entry in a tracert.

[R. J. Salvi]

Post by Sal Bompensaro

Post by Darren New

Post by R. J. Salvi
10.69.128.1
Anyone know why? Thx.

That's your modem.

My first hop is always 10.71.0.1.
I don't think it's the modem though. If it were a device on my LAN, the
ping time would be less than 1ms. Instead, it's around 6-10ms. I'm thinking
it's the first gateway that I encounter at Roadrunner.
When you have standard residential-class service, the modem TW gives you
seems to act as nothing more than a "bridge." It doesn't appear to have it's
own address. I noticed, however, that when I had business-class service, I
received a more sophisticated cable modem. That modem had its own IP address
and acted as a router instead of a bridge. In that case, the modem was
always the first entry in a tracert.

My original query was based on my troubleshooting possible latency problems
as my Hop 1 times are around:

74ms 7ms 8ms

If the IP in question is my cable modem, I need it looked at. If it's a
neighborhood node router, I can't do anything about that. Thanks for the
replies.

[Edwin Kruse]

Yes, the 10 dot is the cable modem.

Edwin Kruse
Network Services Manager
TWC San Diego

Post by R. J. Salvi

Post by Sal Bompensaro

Post by Darren New

Post by R. J. Salvi
10.69.128.1
Anyone know why? Thx.

That's your modem.

My first hop is always 10.71.0.1.
I don't think it's the modem though. If it were a device on my LAN, the
ping time would be less than 1ms. Instead, it's around 6-10ms. I'm thinking
it's the first gateway that I encounter at Roadrunner.
When you have standard residential-class service, the modem TW gives you
seems to act as nothing more than a "bridge." It doesn't appear to have it's
own address. I noticed, however, that when I had business-class service, I
received a more sophisticated cable modem. That modem had its own IP address
and acted as a router instead of a bridge. In that case, the modem was
always the first entry in a tracert.

My original query was based on my troubleshooting possible latency problems
74ms 7ms 8ms
If the IP in question is my cable modem, I need it looked at. If it's a
neighborhood node router, I can't do anything about that. Thanks for the
replies.

[Sal Bompensaro]

Post by Edwin Kruse
Yes, the 10 dot is the cable modem.
Edwin Kruse
Network Services Manager
TWC San Diego

So Darren was right ! :)

I'm still kind of surprised that the latency would be so high between
the user's computer and a cable modem on his LAN.

[Ryan Moore]

Post by R. J. Salvi
My original query was based on my troubleshooting possible latency problems
74ms 7ms 8ms
If the IP in question is my cable modem, I need it looked at. If it's a
neighborhood node router, I can't do anything about that. Thanks for the
replies.

Which number are you concerned about? the 7 ms or the 74 ms? It's
certainly possible for the first ping to take extra time if the machine
has to perform an ARP request. That may be the factor you're looking at
here. But even so, on the local LAN 7ms sounds high. You should be able
to get 1 ms or less locally.

Really, these 3 data points aren't enough to figure out if there's a
problem. I would ping that IP address and let it run at least 100 or more
times. That will be a lot more reliable than 3 data points.

If you are seeing high ping times even after doing lots of ping, then
either:

1. The cable modem doesn't respond to ping quickly and it's meaningless.

or

2. You could have a cable issue.

-Ryan

[Darren New]

Post by Ryan Moore
Which number are you concerned about? the 7 ms or the 74 ms? It's
certainly possible for the first ping to take extra time if the machine
has to perform an ARP request. That may be the factor you're looking at
here.

It's not a ping. It's a tracert. That uses an entirely different
mechanism, one that's specifically low priority rather than high
priority. Just for the record.

Use an actual ping instead of a tracert to see.

[Daniel Damouth]

Post by Darren New

Post by Ryan Moore
Which number are you concerned about? the 7 ms or the 74 ms?
It's certainly possible for the first ping to take extra time if
the machine has to perform an ARP request. That may be the
factor you're looking at here.

It's not a ping. It's a tracert. That uses an entirely different
mechanism, one that's specifically low priority rather than high
priority. Just for the record.
Use an actual ping instead of a tracert to see.

My ping to my cable modem always seems to average >10ms, which has
always seemed very strange (and suboptimal) to me. What could possibly
take that much time?

Currently:

C:\Documents and Settings\Dan>ping -n 25 10.71.0.1

Pinging 10.71.0.1 with 32 bytes of data:

Ping statistics for 10.71.0.1:
Packets: Sent = 25, Received = 25, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 7ms, Maximum = 30ms, Average = 11ms

-Dan Damouth

[Darren New]

Post by Daniel Damouth
My ping to my cable modem always seems to average >10ms, which has
always seemed very strange (and suboptimal) to me. What could possibly
take that much time?

Remember it's not just transmission time you're talking about, but all
the overhead of switching you in and out of the operating system at your
end, the cable modem processing everything coming from the cable, etc.
I'd bet you'd get a faster response if the yellow light wasn't pretty
much constantly on.

Alternately, do you have some NAT-style router (a d-link, a netgear,
something like that)? That'll add some delay in both directions also.

Try "ping 127.0.0.1" and see what you get. That'll give you some idea of
the OS overhead.

Here, I get a consistant 9ms to the modem, <1ms to the IP address
assigned to the local machine.

[Daniel Damouth]

Post by Darren New

Post by Daniel Damouth
My ping to my cable modem always seems to average >10ms, which
has always seemed very strange (and suboptimal) to me. What
could possibly take that much time?

Remember it's not just transmission time you're talking about, but
all the overhead of switching you in and out of the operating
system at your end, the cable modem processing everything coming
from the cable, etc. I'd bet you'd get a faster response if the
yellow light wasn't pretty much constantly on.
Alternately, do you have some NAT-style router (a d-link, a
netgear, something like that)? That'll add some delay in both
directions also.
Try "ping 127.0.0.1" and see what you get. That'll give you some
idea of the OS overhead.

No router, ping to localhost is <1ms, transmission time must be <1ms,
leaving me to conclude that the delay is caused almost entirely by the
modem.

-Dan Damouth

[Kenyon Ralph]

Post by Daniel Damouth
No router, ping to localhost is <1ms, transmission time must be <1ms,
leaving me to conclude that the delay is caused almost entirely by the
modem.

I don't think the cable modem's ping delays indicate anything of
significance. Here's why.

Pings to my cable modem:

--- 10.69.128.1 ping statistics ---
240 packets transmitted, 240 received, 0% packet loss, time 239266ms
rtt min/avg/max/mdev = 5.600/8.373/40.245/3.809 ms

Pings to a host on the Internet:

--- 4.2.2.1 ping statistics ---
241 packets transmitted, 241 received, 0% packet loss, time 240280ms
rtt min/avg/max/mdev = 6.635/9.369/23.147/2.789 ms

There's actually LESS variation in the pings to the Internet host than there
are to the cable modem (as indicated by the standard deviations)! Also,
look at the traceroute for the Internet host:

traceroute to vnsc-pri.sys.gtei.net (4.2.2.1), 30 hops max, 40 byte packets
1 192.168.0.1 (192.168.0.1) 0.174 ms 0.180 ms 0.139 ms
2 10.69.128.1 (10.69.128.1) 26.212 ms 6.117 ms 8.109 ms
3 bwsdca1-rtr1-ge2-1.san.rr.com (24.25.192.182) 6.319 ms 9.667 ms 6.150
ms
4 WCSDCA1-GSR3-SRP0.san.rr.com (24.25.196.2) 8.479 ms 16.522 ms 7.724
ms
5 so-0-0-0-0.gar1.SanDiego1.Level3.net (209.0.8.1) 8.485 ms 8.293 ms
87.276 ms
6 so-7-0-0.mp2.SanDiego1.Level3.net (4.68.113.69) 7.217 ms
so-7-0-0.mp1.SanDiego1.Level3.net (4.68.113.93) 11.952 ms 75.236 ms
7 so-10-0.hsa1.SanDiego1.Level3.net (4.68.113.38) 8.288 ms
so-8-0.hsa1.SanDiego1.Level3.net (4.68.112.130) 11.616 ms
so-10-0.hsa1.SanDiego1.Level3.net (4.68.113.38) 9.642 ms
8 vnsc-pri.sys.gtei.net (4.2.2.1) 10.053 ms 8.228 ms 7.346 ms

This host is 8 hops away, yet only has an average ping time of about 1
millisecond greater than the cable modem!

Also note that I ran these tests while my brother was playing World of
Warcraft online, and I was doing a bit of web surfing.

I believe you might even be able to find a host on the Internet with LOWER
average ping times than the cable modem. So the cable modem's pings are
really NOT a good indicator of your network's performance.

[Kenyon Ralph]

I get a very similar traceroute to yours to that host. But doesn't
it imply that the vast majority of the latency comes from the cable
modem?

Yeah actually that makes more sense. I guess since everyone seems to have
this delay due to the cable modem, that's just the way it is with the
current system? Maybe cable modems with faster processors would lower the
delay?

[R. J. Salvi]

Post by Darren New

Post by Ryan Moore
Which number are you concerned about? the 7 ms or the 74 ms? It's
certainly possible for the first ping to take extra time if the machine
has to perform an ARP request. That may be the factor you're looking at
here.

It's not a ping. It's a tracert. That uses an entirely different
mechanism, one that's specifically low priority rather than high priority.
Just for the record.
Use an actual ping instead of a tracert to see.

Pinging the modem (10.69.128.1):

66ms
8ms
8ms
9ms

Normal...?

[R. J. Salvi]

Post by R. J. Salvi

Post by Darren New

Post by Ryan Moore
Which number are you concerned about? the 7 ms or the 74 ms? It's
certainly possible for the first ping to take extra time if the machine
has to perform an ARP request. That may be the factor you're looking at
here.

It's not a ping. It's a tracert. That uses an entirely different
mechanism, one that's specifically low priority rather than high
priority. Just for the record.
Use an actual ping instead of a tracert to see.

66ms
8ms
8ms
9ms
Normal...?

It turned out to be the modem (SB4100). It was switched out for an SB5100
and my first hop is now 5-7ms. Happy camper, although I'm wondering why I
NEVER hit 8Mbs with the Premium Service. 7.6Mbs, yes, 8Mbs, no...