Rookie

Gigabit speed issues

I had my service upgraded yesterday to the new gigabit offering in my area - technician was here for 3-4 hours, and seemed to be fairly unsure of what he was doing, he said he had only done one of these install and only received 30 minutes of traning on it, had to call and ask how to get readings from his meter several times, etc. Finally after getting the new modem provisioned after a couple of hours, he couldn't get any decent download speeds from it, and called someone else to take a look at the pole. The tech that came out for the main line said that everything looked good and he was getting about 900 down at the pole.

 

I'm am getting between 45-95 down depending on the time of day, hard wired to the modem with a gigabit ethernet port on a new laptop. Upload speeds look good. I'm posting the modem signals and speedtest results here, along with several of the errors that come up every time I restart the modem, but don't seem to be thrown at any point after boot, hoping someone can shed some light on the possible speed issues.

 

Errors during boot:

 

 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;

"SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period

"No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;

 "No Ranging Response received - T3 time-out;

 "Unicast Ranging Received Abort Response - Re-initializing MAC

 "No Ranging Response received - T3 time-out

11 REPLIES
Rookie

Re: Gigabit speed issues

Some further info:

 

Location: 41075

Services: Gigabit Internet only, no TV or phone

Modem: Technicolor TC4400

Software version: CHR_SR70.14.04R1

Recent changes: Upgraded to Gigabit from standard internet plan, previously had my own modem (SB8200), speeds are now slower than they were on the standard plan

Testing environment: 1 grounding block/splitter outside the house, terminated properly, cable runs directly from that splitter to the modem, no other splitters or hardward. CAT5e and CAT6 cable were both used to test connected to both a gigabit and a 10G ethernet port, same speeds on either device. 

 

Update to the signal and uncorrectable count 3.5 hours after reset:

 

I6PBual

Valued Contributor

Re: Gigabit speed issues

Have you confirmed the active link speed of the ports? IF there are LED's on the port, one will give an indicator of the link speed, like solid white or green for Gbit, or solid/flashing amber for a 100/10Mbit link speed.

Auto-negotiation could be failing somehow.... setting the speed manually MIGHT work, depending on why auto is failing to lock in gigabit speed.
Rookie

Re: Gigabit speed issues

Yep - connected at gigabit via both ports I've tried on 2 different machines.

Valued Contributor

Re: Gigabit speed issues

Might be worth trying to manually set the NIC to gigabit and half-duplex manually in the drivers just to see if there is any significant change. Just curious if it might be something wonky in the NIC and/or Winblows stacks causing something funky.

For that matter, may want to double check the congestion control (autotuning) setting as well.... just in case you may have gotten hit by that glitch people were having with a Winupdate:

Netsh Interface Tcp show global

(remember, need an admin command prompt if you want to try manually setting it to normal or experimental)

Just trying to rule out some possibilities that might exist at the system level. Nothing like missing something on the client side that leaves you spinning your wheels trying to find a gremlin upstream.

Spectrum Employee

Re: Gigabit speed issues

Allow me to be more clear, and edit this response before anyone else needs to comment repeating each other for emphasis on my former response...

 

T-3 timeouts, when CONSTANT, yes, can indicate a serious issue, however, T-3 timeouts without the presence of T-4 timeouts, 99% of the time, do not warrant a truck roll (technician appointment.)

If a full CMTS modem report were run investigating issues with flaps, packet loss, etc, I'm sure there would be even more indicators to cause a tech to be scheduled..

But my point was that T-3's dont always= horrible service and issues.  Best thing you can do is print the modem reports, and keep them on hand for the tech when he comes out.

 

When migrating from one pricing package to another, or upgrading speeds, yes, it can take up to 24 hours to see a speed increase..  Customers are always told to power cycle equipment properly, and wait 24 hours to see the full increase in speeds.

However, like I said, with this being a Gig upgrade, which requires a completely different set up, and mandatory technician install, that's not the case.. So per my last comment, calling Spectrum to submit a ticket, and get a technician to go back and finish the job ensuring the set up is correct is the best solution, no? As, clearly, it is a setup/ coax/ line issue.

And, my bad on the comment about devices being incapable of seeing those speeds.. You'd be surprised at how many people run a speed test on their gaming system, or laptop with a threshold much lower than the subscribed speed, wondering why they're not seeing the exact speeds on that device. There are many factors that cause speeds to not reach the subscribed speed is my point.

The second the speed did not reach subscribed levels,  especially hardwired after install, the tech shouldve been scheduled to go back. If you call within that first 24 hours, you can get fit in quicker where dispatch can fit ya in =)

 

Thanks

 

-c

 

Rookie

Re: Gigabit speed issues

For the benefit of anyone else finding this thread:

“Usually takes about a day for your speeds to jump up.”
This is completely false.

“ no single device is capable of 940 mbps anyway.”
Also completely false.

“They read kinda scary sounding but they’re pretty normal as far as modem reads go.”
Fairly sure that constant T3 timeouts aren’t normal or desirable as far as logs go.
Helper

Re: Gigabit speed issues


@AaronBr wrote:
For the benefit of anyone else finding this thread:

“Usually takes about a day for your speeds to jump up.”
This is completely false.

“ no single device is capable of 940 mbps anyway.”
Also completely false.

“They read kinda scary sounding but they’re pretty normal as far as modem reads go.”
Fairly sure that constant T3 timeouts aren’t normal or desirable as far as logs go.

You couldn't be more right...speed jumps are instant once provisioned and a reboot occurs (assuming equipment is compatible), many devices are capable of gig speeds, and constant T3 timeouts usually indicate pretty serious coax issues.

Highlighted
Established Sharer

Re: Gigabit speed issues

Add one more to the forum's "lessons learned" list for new Gigabit service:  If any one of the four pairs of wires in your ethernet CAT-5e cable is defective or loose, the interface will only auto-negotiate to 100 Mbps, not at a full Gig. 

There are a lot of really crappy counterfeit cables being made in China that come into the USA marked as CAT-5e.  This is not a matter of needing more expensive CAT-6 or CAT-7 patch cables; CAT-5e is designed for up to 1 Gigabit. 

Valued Contributor

Re: Gigabit speed issues

For this teason, I am curious if the OP actually verified the actual link speed in play, and/or if there was any difference when setting the link speed manually to gigabit/half-duplex.