Posting an update to my earlier posts concerning my problems with Coda modem losing OFDM lock shortly after reboot, resulting in dramatic loss of bandwidth.
Senior "supervisor" arrived and did troubleshooting, swapped out various connectors, swapped out the modem, problem continued. Then he took the modem outdoors, to the cable "tap" out on the curb a few homes down the street, connected it there, and problem continued. At that point, he could go no further and had to open another maintenance ticket.
A few days later, he told me that maintenance traced the problem to the segment between the "node" and the "tap" and that it would be a "big job" to fix this segment so it is likely not going to happen anytime soon. He brought me an older CGN3ACR modem, which is a Docsis 3.0 modem, only 24 channels without OFDM and it has been running fine now for almost a week without issues. This is ok for me since I'm getting close to 200Mbps and I do not need the higher speeds. Gigabit internet would not work on this tap until they can repair the noisy segment. Be careful about this in your area if you are upgrading your packages or your modems because the Coda's need a very clean signal to work properly, and they are not smart enough to handshake with the CMTS on a different protocol when they are experiencing problems. No doubt the Coda could have run properly on 32 channels on Docsis 3.0 without OFDM but either it isn't programmed to do that (or the CMTS isn't telling it to) when problems are experienced on the line.
No repair here, but at least we have a workaround for now. The "supervisor" guy was very helpful. Finally someone took the issue seriously after about 6 months of back and forth with the call center.
@wes162 if you were to swap out the CGN3ACR for a CGNM-3552 which is a 32 channel modem, you should see very close to 950 Mb/s on the downstream side.
In theory, the CODA-4582 should run 32 channel DOCSIS 3.0 without any issues. This makes me wonder if there is some issue with the DOCSIS 3.0 side of the modem. On the other hand, if there are major issues between the tap and the CMTS, then its possible that gigabit DOCSIS 3.0 operation isn't possible either.
The tech that just visited me said that OFDM, even on the downstream, only improves upstream performance. I try not to make it a debate - especially since I don't know anything for sure anyway - but it didn't pass my HowShouldThisThingProbablyWork smell test.
When I lose OFDM on the CODA, I can't break 300Mbit.
OFDM is just a form of signal compression, squeezing more data into a tighter RF spectrum. It can work both upstream or downstream, but I think the Rogers cable modems and CMTS's are programmed only to use it for the downstream channels. There isn't too much need for it on upstream since most customers aren't running server farms that need lots of upstream.
Right, he insisted that the downstream OFDM compression's only purpose was to provide more room to the upstream -- I didn't buy that explanation, but I didn't want to argue with someone who was being otherwise much more helpful than those that preceded him.
Interesting.... OFDM is much more resilient to noise than SC-QAM and despite having the .33 firmware, you still get the loss of OFDM lock.
If you are on the plans that are below the Ignite Gigabit plan, I wouldn't worry too much. OFDM increases the bandwidth on the downstream literally by tenfold when compared to DOCSIS 3.0; it really only enables Rogers to deliver a consistent 1Gbps for their Ignite Gigabit subscribers. (As a gamer I see this in a totally different way b/c it actually reduces ping times due to it being much more resilient to noise and less prone to packet dropping during peak times due to the substantial amount of bandwidth it provides).
@daveinsurgent I think the technician was actually referring to OFDM in terms of the upstream side of things. He is technically right. OFDM in the upstream would be called OFDMA and it does provide more bandwidth. DOCSIS 3.0 standards can provide up to 100Mbps on the upstream, but DOCSIS 3.1 brings that up tenfold to 1Gbps. Lots of areas are struggling due to congestion, so this will also help relieve congestion.
How to increaase speed of Hitron CODA-4582U router switched ports:
My configuration is not BRIDGED. Native WiFi is quite fast but "buffers" often making watching streaming sites unpleasant to watch.
I have my AppleTV, Sony AndroidTV and Sony BR player connected directly to the switched ports on the CODA-4582U because these devices are close enough, six feet, expecting this to offload the WiFi traffic. This eliminated the buffering problem. Also there are many, perhaps 35 nearby WiFi access points, that I believe are causing a slowdown of required high speed transmissions over WiFi There are a number of devices, two computers and a printer on WiFi.
I get 150Mb+ download and 15Mb+ upload speeds on my MAC over wifi using the Rogers Test.
Using the NETFLIX connection speed test, I get 100Mb over WiFi
ONLY 50Mb when connected to any of the switched ports.
Also, the modem URL has a settings page, not modifiable, that shows the switched ports at 100M.
Does this have any effect and how can this setting be increased?
I would like to be able to operate the switched ports faster, within QoS limits.
Can QoS be adjusted to allow higher switched port speeds?
@holtzkener, the ports on the modem will negotiate a data rate with the connected device. The 4582 has gigabit ports, so, if you look at the back of the modem, specifically the connected port LEDs, they should be flashing amber for a 1 gigabit connection rate, flashing green for 10/100 Mb/s connection rate. If you're not seeing a 1 gigabit connection rate to a connected device that could be the be the result of:
1. The connected device only having a 10/100 Mb/s port built in; or
2. The connecting ethernet cable has been damaged in some fashion and no longer has all 4 wire pairs in operation to support a 1 gigabit connection rate. That requires all 4 wire pairs in the cable to be connected end to end. Fast Ethernet cables, which some people have hanging around only support 100 Mb/s as they would only have two of the 4 wire pairs connected end to end; or
3. The ethernet cable is not connecting at one or both ethernet ports; or
4. The remote device, despite having a gigabit port, is only set to run that port at 10/100 Mb/s; or
5. If the cable run to the remote device uses house ethernet wiring, then there is a possibility that the wall ports are not connected to all 4 wire pairs at some or all locations; or
6. If a switch is used in conjunction with house cabling, perhaps the switch is a 10/100 Mb/s switch instead of a gigabit switch.
7. If a device is connected to the modem and that device is known to operate at 1 Gibabit/sec with other modems and routers, using the same cable, that points to a port controller failure on the modem. Swap the modem at the nearest Rogers store.
Edit: added item #7.
Hope this helps.
This all sounds good.
The lights on the connectors are amber indicating Gigabit.
What confused me was the fact that the ethernet connection went at speed using the same 6 ft. cable before I upgraded to the 4582 and now is slower. That's why I am looking at the router.
Also, the fact that the wifi is faster made no sense.
I'll try try different cables where I can see all 4 pairs connected and try again.
Thanks a lot. I hadn't considered the cables as a possibility, not did I know what the light's colours meant.
ps do you have a reference to the URL for the manual?
If you're seeing that the device is connecting to the 4582 at 1 gigabit/sec, as evidenced by the port LED, but you're not getting the max data rate out of the modem, there are three other possibilities:
1. you have a signal issue between the modem and the Cable Modem Termination System. The CMTS controls and provides data services to all of the connected Rogers modems in your neighborhood. That includes Cable TV, Internet and Home Phone modems.
2. The modem isn't provisioned properly for the level of service that you have signed up for.
3. The device port is running at 1 Gigabit/sec, but the port transfer rate is set for 100 Mb/s for some reason. That could be an issue with Mac's and Windows pc's, other devices, you would have to check the settings and specs.
To check these items:
1. Log into the modem, navigate to the STATUS .... DOCSIS WAN tab, copy the Downstream table, all the way to the bottom of the OFDM Upstream section. Paste that into a post. The copy and paste process will paste in the text contents of the table. That will allow me to check the OFDM (DOCSIS 3.1) status for the modem.
2. Call tech support and ask the CSR to check the modem and confirm that it is in fact provisioned for your level of service. If you do this, ask the CSR to run a signal check on the modem as well, just to see if it passes or not. If not, you can expect to see a tech at your home within the next few days as arranged with the CSR.
3. Drill down into the device settings to determine the max data transfer rate and set it higher if possible. You might have to check the device specs at this point.
Just to note, if you have subscribed to gigabit service, there are customers who are having issues with that level of service due to issues with the OFDM channel processing. I would expect those that are running the data rate below that shouldn't have huge issues even with OFDM processing issues, but, anything is possible.
Here's a link to an older CGN3 pdf manual. This is getting old at this point, but, it will be close enough except for the newer 802.11ac Wifi settings and items unique to this modem. I don't know if Hitron has produced an updated manual recently but I'll look around.