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Bridging questions

gwilki
I Plan to Stick Around

I have the Cisco DPC3825 Gateway, and have it bridged. All my PC's and devices in the house are wired connected. I have switches to accommodate the extra inputs that I need. For the past few weeks, service has been dropping frequently - sometimes for only a few minutes; sometimes, like last night for an hour or so.

 

Last night I called Rogers tech just to see if there was something going on in my neighbourhood which would cause these outages. The tech said that my line strength was a bit off, but not enough to cause the outages. He proposed pushing a firmware update to the gateway. He also mentioned that the router was more likely the problem.

 

Here are my questions:

 

1. Is there really anything to be gained by bridging the gateway if I am not using wireless connections? It seems the discussions here about the advantages of bridging center around the wireless weaknesses with the gateways.

 

2. Has anyone had any experience with these firmware pushes? I'm concerned that I could be worse off than I am now after it is done.

 

thank you.

GW

 

 

***edited labels***

1 ACCEPTED SOLUTION

Accepted Solutions

Re: Bridging questions

You have cable or connector problems of some type.  The downstream signal levels are a little high, they should be at 0 dBmV. The signal to noise ratios are just at the bottom of the range.  But, you have upstream problems.  You should have three bonded upstream channels and you only have one.  Don't know how the tech missed that.  With only one upstream channel running you will have speed issues, and if that channel goes out, you're hooped.  So, a discussion with tech support with the aim of getting a tech out to your home is necessary.  Don't take no for an answer.



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Re: Bridging questions

Datalink
Resident Expert
Resident Expert

Normally the firmware update is not an issue. If there is an update pending, it will happen at some point whenever the update system pushes it out to your particular area or MAC address, however that is managed. Now that you know it will occur, you can keep an eye out for any strange problems.


If you don’t bridge the modem, that would require you to turn off the DHCP on the router so that the modem handles all of the LAN IP addressing and assign an IP address to the router that is outside of the modem’s LAN IP range so that you can log into the router and make any changes that might be necessary down the road. Its far easier to bridge the modem and run the router as it would normally be run. There are also issues of better control over the various features that your router offers. While the modem might have similar features, typically the router will do a better job, and with better user control. Security is another issue. With your own router, Rogers tech support can’t see beyond your router. Your internal network is private. With the modem running in Gateway mode, tech support can see what is connected. Traffic monitoring is another area where the router offers better capability, depending on what the router can do. Some can give you a running total, by device MAC address, of the amount of data received and transmitted, so you have a better idea of what device is a data hog. You can’t do that with the modem, unless you experiment and run single devices at a time. So, there are definite benefits to running your own router. The question is, do you take advantage of them?

 

Regarding your signal levels, can you log into the modem and copy the DOCSIS WAN downstream and upstream tables and post them into this thread. If you get a drop out in service go back into the modem and copy the same tables and post them again. The target levels are 0 dBmV for downstream signal levels with a signal to noise ratio of approx 36 to 40 dB, and 36 to 40 dBmV for upstream signal levels. The ranges are 0 dBmV + / - 15 dBmV for the downstream side and 36 to 51 dBmV on the upstream side.

 

Edit:  1st line of 2nd para corrected to read:

 

If you don’t bridge the modem, that would require you to turn off the DHCP on the router so that the modem handles all of the LAN IP addressing and assign an IP address to the router that is outside of the modem’s LAN IP range....



Re: Bridging questions

gwilki
I Plan to Stick Around

Thanks much, Datalink. Now that the gateway in in Bridge, how do I log into the modem? The standard 192.168.0.1 no longer works. That gets me into my router.

 

Also when I was talking about unbridging,  I meant to say that I would remove my router from the network. I would have no need for it, since I would have enough ports between the switch and the gateway.

Re: Bridging questions

Gdkitty
Resident Expert
Resident Expert

While in bridge, there used to be a work around way of getting into the settings.. but appears that was removed with the latest firmware.

Really the only way, is to UN bridge it.. to check the levels.

ONLY major advantage otherwise... as long as you dont need any more fancier FORWARDING, NAT or similar functions.. more just basic usage.. the router portion of the them is pretty good. (sometimes your 3rd party may have more options for the above)

Re: Bridging questions

Yep, I forgot about the modem in Bridge business and being unable to log into the modem.  If you want to see what the signal levels are you would have to disconnect the router, plug a pc into the modem and then depress the reset button at the back of the modem to initiate a factory reset.  When that comes back up in Gateway mode, you can log in using the usual default passwords, copy the tables and paste them somewhere temporarily and then reset the modem back to Bridge mode.  While the modem is rebooting, disconnect the pc, and then reconnect the router and pc as you now have them.  Its a bit of work, but you only need to be in Gateway mode for a minute or two and then you can reset the modem back to Bridge mode. 

 

Personal opinion, the only way you are going to know what is going on when your internet service drops out is to be running in Gateway mode so that you can just log into the modem and check the DOCSIS WAN signal levels.  Rebooting the modem, as is done in a change over from Gateway to Bridge mode can reesablish comms with the node, wiping out any useful signal level data that might help diagnose the problem.  You might have something going on that is intermittent, but is getting worse as time goes on.  What you could do for now, is check the signal levels so that you know what they are, and return to Bridge mode.  Keep an eye on how the modem performs and if you see that the problem is getting worse, switch to Gateway mode as I indicated above and run in that configuration so that you can check the signal levels when a dropout occurs.

 

Edit:  corrected to read:

 

Personal opinion, the only way you are going to know what is going on when your internet service drops out is to be running in Gateway mode so that you can just log into the modem and check the DOCSIS WAN signal levels.



Re: Bridging questions

gwilki
I Plan to Stick Around

Tks much to both of you. I believe that I'll start the diagnosis process by letting Rogers push the firmware. If that solves the intermittent outages, I need do nothing more and it was a simple solution.

 

If, however, the outages still occur, I'll unbridge, and take my router out of the network. If that fixes everything, I'll see if I can live only with the features provided by the Gateway. I expect that I will be able to.

 

If all thaf fails, I will get the logs while in Gateway mode and come back here for further help and advice.

 

Thanks again.

 

Grant

Re: Bridging questions


@Gdkitty wrote:

While in bridge, there used to be a work around way of getting into the settings.. but appears that was removed with the latest firmware.

Really the only way, is to UN bridge it.. to check the levels.

ONLY major advantage otherwise... as long as you dont need any more fancier FORWARDING, NAT or similar functions.. more just basic usage.. the router portion of the them is pretty good. (sometimes your 3rd party may have more options for the above)


Is that true even for the DPC3825? Back when I had one, you could http://192.168.100.1/ while bridged and log into it...

 

(If only the CGN3 was that way)

Re: Bridging questions

gwilki
I Plan to Stick Around

VivienM

 

That worked like a charm. I logged into the Cisco and here is the text from the docsis wan table

 

About           
        
        
Model:     Cisco DPC3825
Vendor:     Cisco
Hardware Revision:     1.0
Serial Number:    xxxxxxxxx
MAC Address:     xx:xx:xx:xx:xx:xx
Bootloader Revision:     2.3.0_R3
Current Software Revision:     dpc3825-v302r125572-131113a-ROG
Firmware Name:     dpc3825-v302r125572-131113a-ROG.bin
Firmware Build Time:     Nov 13 15:51:58 2013
Cable Modem Status:     Operational
Wireless Network:    Disable


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

Cable Modem State           
        
        
DOCSIS Downstream Scanning:     *Completed*
DOCSIS Ranging:     *Completed*
DOCSIS DHCP:     *Completed*
DOCSIS TFTP:     *Completed*
DOCSIS Data Reg Complete:     *Completed*
DOCSIS Privacy:     *Enabled*


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

Downstream Channels           
        
        
      Power Level:     Signal to Noise Ratio:
Channel 1:     3.8 dBmV     36.6 dB
Channel 2:     4.2 dBmV     36.5 dB
Channel 3:     4.2 dBmV     36.5 dB
Channel 4:     4.0 dBmV     36.6 dB
Channel 5:     3.6 dBmV     36.5 dB
Channel 6:     4.2 dBmV     36.2 dB
Channel 7:     4.0 dBmV     36.1 dB
Channel 8:     3.6 dBmV     35.8 dB


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

Upstream Channels           
        
        
      Power Level:
Channel 1:     0.0 dBmV
Channel 2:     0.0 dBmV
Channel 3:     34.5 dBmV
Channel 4:     0.0 dBmV

 

I have no clue what any of this means, so I would be grateful to anyone that can tell me if it points to something wrong.

 

Grant

Re: Bridging questions

You have cable or connector problems of some type.  The downstream signal levels are a little high, they should be at 0 dBmV. The signal to noise ratios are just at the bottom of the range.  But, you have upstream problems.  You should have three bonded upstream channels and you only have one.  Don't know how the tech missed that.  With only one upstream channel running you will have speed issues, and if that channel goes out, you're hooped.  So, a discussion with tech support with the aim of getting a tech out to your home is necessary.  Don't take no for an answer.



Re: Bridging questions

Oops, sorry our right, its only the CGN3 that you cant access anymore.  I thought they had it for a second, my bad.


I agree with datalink on the signal problems..  Bad juju on the upstream side.

Re: Bridging questions

gwilki
I Plan to Stick Around

Thanks again , Datalink. Rogers is sending a tech here tomorrow morning. I'll post back with results.

Re: Bridging questions

Yes, please post the signal levels when all is said and done, just to see how they turned out.  Your modem is basically in survival mode with one upstream channel running.  The sooner that is fixed, the better.

 

Can you see if you can go back into your data posting (msg #8) and delete your MAC address.  If you can't, I'll ask one of the moderators to do it.



Re: Bridging questions

gwilki
I Plan to Stick Around

The Rogers tech just left - good guy. He changed some connectors outside. It's darn cold to be doing that. Inside, he put an attenuator on the modem.

 

Here are the new numbers.

 


        
        
      Power Level:     Signal to Noise Ratio:
Channel 1:     3.2 dBmV     37.1 dB
Channel 2:     3.3 dBmV     37.2 dB
Channel 3:     3.3 dBmV     36.9 dB
Channel 4:     3.2 dBmV     36.9 dB
Channel 5:     3.0 dBmV     36.7 dB
Channel 6:     3.7 dBmV     37.2 dB
Channel 7:     3.6 dBmV     36.9 dB
Channel 8:     3.3 dBmV     36.7 dB

          
Upstream Channels           
        
        
      Power Level:
Channel 1:     41.7 dBmV
Channel 2:     41.5 dBmV
Channel 3:     41.0 dBmV
Channel 4:     0.0 dBmV

 

Thanks to you all for your advice. I'm grateful.

 

Datalink: Tks for the prompt about my MAC. I know better than that. Duh!!

 

Grant

Re: Bridging questions

Gdkitty
Resident Expert
Resident Expert

In a perfect world you would want the downstream closer to zero.. that is pretty darn good though generally 🙂
The upstream looks ALOT better.

Re: Bridging questions

gwilki
I Plan to Stick Around

GdKitty: From the previous posts, I knew that 0 would be better, but at least I have a big improvement in the upstream.

 

Can you please tell me, could the larger than 0 numbers have anything to do with my equipment - router, switches, etc. Or, are they strictly a function of the incoming signal from Rogers? We are using a strictly wired connection network. But, that means that we have switches in the upstairs rooms to take the input from 2 PC's in the room to one jack in the wall. Then, I have  switch beside the basement router because I have more inputs than the router can take. Then, I have the router connecting to the bridged Gateway/modem. I'm just trying to learn if having all these connections can affect the numbers.

 

Grant

Re: Bridging questions

There will not be any effect from your internal network.  The DOCSIS WAN data is stricly a reflection of the incoming signal, after it has travelled from the local node, to the tap, through three or four connectors and finally to the modem.  Normally, with the cable loss from the node, and tap, and losses through the connectors, you would end up around 0 dBmV.  But, that depends on your distance from the node, as I believe the node ouput is constant.  The actual output is ramped up from low to high frequency to counter the corresponding loss in the cable run from the node, to the tap and to the home.  Over time, the numbers will drop as the cable to the home and connectors age.  And then, when that eventually does happen, it will be time for another tech visit.  🙂



Re: Bridging questions

DrMike
I'm a Trusted Contributor

Might be a dumb question but now that my CGN3 is in bridge mode, is there any way to access any of its features via browser. Obviously 192.168.1.1 takes me to the admin page of my ASUS AC68U.

 

I had seen in some other threads that for older modems (cisco?) you could use 192.168.100.1 to access the modem itself even after bridging, but that doesn't work for me on the Hitron.

 

So, just out of curiosity, is there any way to access the CGN3? 

 

Not sure I know why I want to do this, just curious to learn new things 🙂

Re: Bridging questions

DrMike
I'm a Trusted Contributor

And now I see from reading the earlier notes in this thread that there does not seem to be any way to access the CGN3 until and unless it is reset to factory and re-established as a gateway.

 

One more strike against the Hitron, but it seems I have my answer. 

 

Thanks anyway. 

Re: Bridging questions

192.168.100.1 used to access the CGN3 when it was running in Bridge mode.  The last firmware update nuked that capability.  Hopefully it will return in the next update.

 

192.168.100.1 does work and allows access to the CGN3ACR when it is running in Bridge mode.  This has been tried and confirmed.



Re: Bridging questions

baffledalot
I Plan to Stick Around

Hi Datalink

 

thanks for all of the great advice... and others on this thread.

 

With respect to getting the up and down link signal strength and noise data.. is there any way of getting this from a CGN2 in bridge mode... I am having intermittent connection issues in bridged mode...

Re: Bridging questions

You can try via

192.168.100.1

but if that doesnt work.. you would have to reset it back to gateway to check it.

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