Separate router and wireless access point?

[rmiller1959]

I am considering purchasing a Cisco RV180 VPN router for my home office, and I already have an ASUS RT-N56U that I would convert into a wireless access point. I've been having issues with sporadic and frequent dropouts of my Internet connection and, while I haven't completed my troubleshooting, I'm looking at all possibilities for upgrades/replacements.

I recall reading somewhere that the optimal networking solution is to have a separate router and wireless access point for reliability. Is this true, or does it matter?

Thanks!

 

[thetoad30]

I am considering purchasing a Cisco RV180 VPN router for my home office, and I already have an ASUS RT-N56U that I would convert into a wireless access point. I've been having issues with sporadic and frequent dropouts of my Internet connection and, while I haven't completed my troubleshooting, I'm looking at all possibilities for upgrades/replacements.

I recall reading somewhere that the optimal networking solution is to have a separate router and wireless access point for reliability. Is this true, or does it matter?

Thanks!

This depends on how much you use each separate function.

That Asus router has a pretty hefty CPU, by router/wireless AP standards. Unless you have hundreds of clients using the maximum routing (100-1000mbits/s) you're unlikely to be overloading the CPU.

Stability is another story completely, however. If you're needing four-nines reliability with a connection, then you start with the router by going business-grade, go pay for Internet service via a T1 bundle that guarantees up-time, and then use a business-grade AP.

From the sounds of it, you might have either a defective router, unstable Internet, or maybe need an upgrade to the router's firmware.

Can you explain in more detail where you're dropping connection? Is it truly the Internet (WAN) connection going down on the router, or are you losing it while on wireless, etc.? More specifics can help troubleshoot.

 

[stevech]

... I've been having issues with sporadic and frequent dropouts of my Internet connection and, while I haven't completed my troubleshooting,

Thanks!

Tested to confirm it's the WiFi and not your ISP? (Using PC connected by wire to router).

Checked if router is failing to renew DHCP with modem?

 

[rmiller1959]

Next steps

Those are steps I plan to take, although I need to be able to catch it at just the right time!

 

[rmiller1959]

I should be clear that the random dropouts are not related to the Wi-Fi portion of the router, because they normally happen while I'm on my desktop, and it seems that everyone in the house (four desktops) loses the connection at the same time. None of us are on Wi-Fi, since all my systems are using the Netgear XAV5001 Powerline adapters. I've run the Windows 7 troubleshooter, which never seems to find anything, and I usually check the powerline adapters using the provided Netgear utility, and it tells me they're still transmitting. The Windows network and sharing center tells me I have network connectivity but no Internet connection. So I'm assuming it's either:

1) My ISP (Comcast)
2) The cable modem (Motorola SB6120)
3) The router (ASUS RT-N56U)

The cable modem has some log entries with the following language (these are from July 8 to 10, with the most current at the top):

DCC aborted unable to communicate on new upstream channel
Unicast Ranging Received Abort Response - initializing
No Ranging Response received - T3 time-out
SYNC Timing Synchronization failure - Loss of Sync
No Ranging Response received - T3 time-out
REG RSP not received
Timeout and retries exceeded
Registration RSP rejected unspecified reason
No Ranging Response received - T3 time-out
DCC-ACK not received
No Ranging Response received - T3 time-out
REG RSP not received
T6 Timeout and retries exceeded
Registration RSP rejected unspecified reason

Does this information help better pinpoint the problem?

 

[stevech]

those cable modem log entries are OK.
On the modem, just ensure that the SEND and RECV lights are on when you are having trouble.
My cable modems (Time Warner) respond to this, from your browser (despite the subnet differences)
192.168.100.1
And if that yields a web page for the router, look on the SIGNAL tab (or some such name).
The downstream (from cable network) signal should something like -10 to 0 dBmV. It won't vary much. It'll depend on how many splitters are between the modem and the cable entering your home (keep it to one two-way ahead of the modem).

The upstream signal is problematic: it will vary according to noise and loading and weather. Should be a number between about 40 and 50dBmV. Look often. If it gets to 55 or more, that means the upstream (modem to network) is marginal. If it stays long at 55 or 58 or so, the SEND light will go out and your modem has "lost synch on the upstream". Again, keep the number of splitters to one two-way between the main incoming coax and your modem.

This is for the DOCSIS 2 standards in modems, which is service at up to 20Mbps or so down and 1-3Mbps up (often, limited to 1Mbps up by the ISP).

D0CSIS 3 is in a few systems, with faster speeds, higher prices.

Hopefully the ISP, not you, owns the modem. The ISP can interrogate the modem signal levels. Watch the upstream in the evening busy hours and when the weather is unusually warm. That seems to adversely affect the cable plant infrastructure and cause signal problems.
The key though is the number of splitters and avoiding 3 way or 4 way splitters in the path to the modem.

 

[sfx2000]

Check your cable modem and connectivity - problem there it is...

Sounds like poor signal coming in - and perhaps a truck roll from Comcast - had a similar issue with CoxHSI, and found it was a bad connection on their side (physical connection), they ended up running new cable from their box to the house on their dime.

 

[rmiller1959]

I own the modem

those cable modem log entries are OK.
On the modem, just ensure that the SEND and RECV lights are on when you are having trouble.
My cable modems (Time Warner) respond to this, from your browser (despite the subnet differences)
192.168.100.1
And if that yields a web page for the router, look on the SIGNAL tab (or some such name).
The downstream (from cable network) signal should something like -10 to 0 dBmV. It won't vary much. It'll depend on how many splitters are between the modem and the cable entering your home (keep it to one two-way ahead of the modem).

The upstream signal is problematic: it will vary according to noise and loading and weather. Should be a number between about 40 and 50dBmV. Look often. If it gets to 55 or more, that means the upstream (modem to network) is marginal. If it stays long at 55 or 58 or so, the SEND light will go out and your modem has "lost synch on the upstream". Again, keep the number of splitters to one two-way between the main incoming coax and your modem.

This is for the DOCSIS 2 standards in modems, which is service at up to 20Mbps or so down and 1-3Mbps up (often, limited to 1Mbps up by the ISP).

D0CSIS 3 is in a few systems, with faster speeds, higher prices.

Hopefully the ISP, not you, owns the modem. The ISP can interrogate the modem signal levels. Watch the upstream in the evening busy hours and when the weather is unusually warm. That seems to adversely affect the cable plant infrastructure and cause signal problems.
The key though is the number of splitters and avoiding 3 way or 4 way splitters in the path to the modem.

Thank you for the troubleshooting steps. I own the modem, for what it's worth. It's a DOCSIS 3 modem I purchased in Maryland, where I had access to higher speed Internet service from Comcast than I do here in central Virginia.

 

[rmiller1959]

I see four bonding channel values (201-204) and the S/N ratio is 38dB-39dB. The power level on the four channels is 3dBmV-4 dBmV. Does that help?

 

[tipstir]

Dos that CM offer you CM Status for the Docsis-Downstream Scanning

I use to be on COXNET now on COMCAST but I did leave my cable modem behind which I got for free no rental charges on that one. But not with COMCAST like $7 a month for this RCA larger cube design. Seems to have a battery backup inside. RF Coax, RJ45 100MB Port, VOIP on this one. But this is how they dealing it to me below. I had them completely redo my house here cable wise and also install a box. On their dime they had to run a new drop from the box (which is my property here) to my house which had to be near where the electric comes in for grounding. The old way was like I was just adding cable with a 4 way splitter. That's gone.

RF Parameters
Downstream
Frequency 597 MHz Power 3 dBmV
Signal to Noise Ratio 38 dB Modulation QAM256
Upstream
Frequency 36.500 MHz Power 45 dBmV
Upstream Data Rate 5120 Ksym/sec Modulation QAM64

 

[claykin]

Here's what I'd recommend.

1) Stevech gave you excellent advice regarding signal levels. Upstream is usually a problem before downstream. You can contact Comcast support and ask them to read you your current readings. They can probe your modem and report back your signal level.

2) Find where Comcast comes into your premise. Is there a splitter? How many ports? Does the splitter says its frequency range is 5-1000Mhz or greater? Where is your cable modem located? At first splitter or at a jack fed from one of the splitter ports? Is there a second splitter near the cable modem? Again, is it 5-1000Mhz or greater? Are ALL coax cables RG6? Are ALL coax cables (including those in wall) finished with compression RG6 fittings?

3) Another question would be the coax barrels. If you have older wall plates, these older barrels can be problematic. They can attenuate the signal at higher frequencies.

4) Is there a cable amplifier anywhere in your premise? I so, make and model and where is it located.

5) The powerline adapters can be part/all of the problem. Some devices emit noise from time to time and can mess with powerline networking. Some electronics have noisy switching power supplies that can ocassionally inject enough noise to cause powerline networking issues. Same can be true for some motorized products such as a refrigerator and air conditioner. Try to see if the problem happens when some device is on/off or when it turns on/off.

Hope this helps.

 

[stevech]

My Time Warner techs will come to the home and check all in-house cabling, splitters, quality of cable, connectors, etc. They will fix and recommend so as to get the cable modem signals where they should be.

Here's the path I designed long ago:
Cable enters my home and goes to...
Two-way high quality splitter
One side of splitter goes 50 ft. of coax to cable modem in garage.
Other side of splitter goes to an amplifier that feeds splitters and TVs and set top boxes.
That amplifier was provided by the cable company ($0) so there's no finger-pointing. It has a return path (no gain) for the upstream signals from the cable modem and from the set top boxes (video on demand, Switched Digital Video).

Don't put cable modem downstream of the amp.

Assuming that you do not have, as I did, a problem beyond my control and beyond Time Warner's control: My coax runs from my attic through the attics of 3 adjacent common-wall townhomes, in a 4 unit building. After a 2 year battle with Time Warner Cable (TWC) and my homeowner's association, one TWC supervising tech that I made a plea to solved it. I helped him get an OK to enter the attics of neighbors (that I knew). He found a 4-way splitter in MY coax in my neighbor's attic. Been there for 15 years. Removing it cured my shaky cable modem and marginal HDTV. Still not as good as it should be, but that's because my cable run to TWC's "demarcation" is almost 100' of old crappy RG59, and its politically almost impossible to get it replaced.

Here, TWC does not permit customer-owned cable modems. They have DOCSIS 2. My speeds are more than adequate for my needs. As a part of the phone/HDTV/Internet bundle, I pay about $42/mo for cable modem service. Cable modem rental isn't itemized in the bill. They change out the modem any time I holler. About every 2 years. Just changed from Motorola (GI) SB 5xxx to an Aris phone/modem combo. I used to have the Aris + a separate cable modem, but that requires another splitter.

 

[tipstir]

Comcast charges extra for what your doing. RG6 Ultra Coax @ 2.3GHz (2300MHz) Shielded is what they use. The two-way splitter you have mentioned is correct. They can give you 4-way power amp but that's only needed if you single is weak. In my prior house Cox had installed two of these amps then again I had 8 drop connections. I've notice that Comcast doesn't like to feed direct line of Coax they like to use joiners (female to female) To me that degrade your signal.

 

[rmiller1959]

We own the cable modem but not the house

Thanks to everyone for the suggestions. I will definitely look into the connection from Comcast to see if that's where the problem lies. The previous renters used Comcast for Internet and TV, but we just use it for the Internet. We use DirecTV for our television service,

The issue I have with Comcast is that, if you have a router in the mix, they are quick to affix blame to that device, and it's a royal pain to get them to come out and do anything about it.

My modem and router are in a network rack in the basement of the house. I will go down there and trace the cable path. I'll let you know what I find. Thanks again!

 

[staticfree]

Thanks to everyone for the suggestions. I will definitely look into the connection from Comcast to see if that's where the problem lies. The previous renters used Comcast for Internet and TV, but we just use it for the Internet. We use DirecTV for our television service,

The issue I have with Comcast is that, if you have a router in the mix, they are quick to affix blame to that device, and it's a royal pain to get them to come out and do anything about it.

My modem and router are in a network rack in the basement of the house. I will go down there and trace the cable path. I'll let you know what I find. Thanks again!

Well you can connect one of your PC's directly to your cable modem to see if you still get the internet connection drop outs. That will eliminate the router as the cause and you would have isolated it for sure that it is a cable ISP problem. Then you can tell them that you do not have a router connected and they have no excuse but to come out and repair or replace the bad cabling or cable modem. But if your PC works fine directly connected to the cable modem then maybe the router is the problem.

 

[rmiller1959]

I will test the direct connection tomorrow...

...but in the meantime, I ran downstairs and checked the lights on the cable modem twice when sudden dropouts occurred, and they are basically going crazy, cycling and blinking as if it's trying to acquire a signal. Within 30 seconds or so, it appears to reset and go through a typical power cycle before it becomes operational again. To me, that suggests a cable modem or ISP signal problem. Am I off base?

 

[tipstir]

...but in the meantime, I ran downstairs and checked the lights on the cable modem twice when sudden dropouts occurred, and they are basically going crazy, cycling and blinking as if it's trying to acquire a signal. Within 30 seconds or so, it appears to reset and go through a typical power cycle before it becomes operational again. To me, that suggests a cable modem or ISP signal problem. Am I off base?

Get them on the phone tech tier 3 who knows what your talking about. They'll tell you to reset the modem. The correct way is to have them on the phone when you do it. This is how I use to do it with COX. They can connect issues on their end if need be? Cable Modems are suppose to be reset every month. I do it every 6 months. Check the logs in your cable model should be 192.168.xxx.100

What you have is an issue. They need to come out if you have that service agreement on your contract with them. Otherwise it's going to cost you with Comcast. If they're late you can make money from them too. So now they're on time.

 

[rmiller1959]

Traced the cable connection...

...and found that it appears to have one barrel connector linking two coaxial cables, and the cable leads to a Comcast box outside where there is a DirecTV SWM 2-way splitter (2-2150 Mhz), presumably to separate the Internet connection from the TV connection. Both cables run into the ground from the box, so that's as much as I was able to see. I hope this is useful information.

 

[stevech]

as suggested earlier, can't you get the cableCo to come out at no cost to CORRECT the recurring loss of modem sync? If the SEND or RECEIVE lights blink, esp. the latter, THEY need to fix the problem on their nickel even if it's cable faults indoors. It may be too that they are providing a too weak signal.

Do you see high (50 or more) on `192.168.100.1 signal strength reports? It will vary widely by day and time.
[ ] yes
[ ] no

 

[rmiller1959]

Comcast is coming on Wednesday...

...to look at the problem. They said if my cable modem is the problem, they will charge me $85 for the visit since I own the modem. If it's their lines, it's free of charge.

I wonder what it will be if the DirecTV installer did something to mess up the Comcast connection?

I bought a Comcast SB6121 cable modem to test if the modem is the problem. I don't want to be charged $85 and still have to replace the modem, and I can return the new modem if that's not the problem.

I'll look into the signal strength reports when I get home.

Thanks for your advice!