CMTS/Public Wifi provisioning question

I expect Frank Bulk to have an opinion on this, all others welcome.

Hat tip to Bright House -- I've noticed lately that I don't have to go
through their captive portal when using their public wifi hotspots (they
participate in the CableWifi consortium, using WAPs built into their
6580 and other cablemodems, and offer a carrier-specific connection SSID
as well).

This has led me to a point of curiosity:

If I'm the subscriber, and I've paid for 15 mb/s down, then my wired
connection and my private wireless (if provisioned, and they charge
$10/mo, so I'll do that myself, thanks) are using one ... DOCSIS path?
back to the CMTS.

I assume that cableco provided voice is on a separate path, and I'm sure
the TV service is -- if it's even IP at all.

But the question is: is that public wifi service *also* on a separate
bandwidth-limited channel out of the cablemodem?

Offline replies fine, unless you think it's of sufficiently general
interest; I expect it's implementation dependent.

-- jra

On list would be awesome, I'm also interested in this!

It's my understanding that the public Wi-Fi uses the same data flow as the subcriber's data flow. I've seen nothing in the release notes for ARRIS or Moto that suggest one can tie an SSID to a specific service flow.


From talking to folks involved with and Comcast

support there is a separate service flow for the public SSID. I have yet
to configure that in the lab, but it sounds like a good project :slight_smile:

Scott Helms
Vice President of Technology
(678) 507-5000

Interesting, I may need to open a ticket with Moto to ask how that’s done.


If folks have questions - happy to assist - my team manages the
engineering of our WiFi network (in home & out of home). Just send me a
note off-list.

Jason Livingood

DOCSIS config files allow one to use service flow classifiers that match on a variety of criteria. I imagine either the IP range used for public access or the SSID/VLAN/Interface of the wifi hotspot could be used in this instance. provides a good general overview of what's available and how to apply (see section 6 on classifiers).

Of course, even if a dedicated service flow is used, this could still compete with the bandwidth available to the modem or to other modems served on the same node. I could envision this making network bandwidth management more difficult as customers roam, especially if they densely congregate.


Frank Bulk wrote the following on 5/29/2014 10:27 PM:

That’s what I was thinking, I'm not sure about the specifics of the implementation in question but the SSID may have a unique tunnel address(back to a wireless controller) which *could* be used to tag the flows with a specific SCN.