Telo after switch + Cox Internet

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Joined: Sat Sep 25, 2010 9:17 pm

Telo after switch + Cox Internet

Post by Troyjoy » Sat Jun 29, 2013 10:28 pm

OK, it took me 4+ hours today to figure out what I'm going to tell you here. I hope it helps someone else get the job done in 15 minutes or less.

Just moved from Verizon DSL to Cox Internet (DSL maxed at 7MB and I usually got about 3-4MB). Installed Motorola Surfboard SBG6580 modem (paid Cox for 50MB and often getting 60+MB—whoa, am I happy!). Ran ethernet Cat 5 cable to Netgear 8-port switch. Connected Telo's ToInternet port (not the HomeNetwork port) to same switch. (Incidentally, also connected my AirPort TimeCapsule to the switch; so both the Telo and the AirPort are at the same level relative to the modem/router.)

All I had to do to make the arrangement work was:
- Log into the Surfboard via (either wired or wireless-on-its-network).
- Determine which IP address is assigned to the port the Telo is plugged into (by running my computer with known MAC address off that port and finding it in the Surfboard's Basic|DHCP listing; in my case it was .114).
- Go to the Surfboard's Advanced|Forwarding page and set the internal IP for .114 by putting all of the port numbers in their respective Start/End|Start/End columns, with 'Both' for 53, and 'UDP' for the next six, and 'TCP' for the last two (as found on this page: ... vice-ports).
- Go to the Surfboard's Advanced|DMZ page and specify .114 as an exposed host. (Here's a quote from an Ooma rep re how secure this is: "No Sir nobody can hack your telo unit, not even us").

Let me describe it another way:
- Coax cable attaches to modem.
- Ethernet cable connects modem to switch
- Telo (and AirPort, and printers, and even another switch plus a downstream wireless router at the other end of the house) plugged into switch.
- Port 3 on that switch happens to be assigned by DHCP.
- So I put .114 in the DMZ, forward Ooma's required ports for .114, and voila'! Everything works as it should.

Another "picture":
WAN via modem --> Netgear switch --> (Telo + AirPort + D-Link + printers + another 8-port switch + other hardwired computers)
Everything works when the Telo is in the DMZ and the required ports are forwarded for it.

I'll bet this concept will work for other routers and switches. You're lucky I'm too worn out to tell you my sob story about how it took 4+ hours and nearly 10 tech calls/chats to get this figured out. May you be blessed!

PS - Props to EX Bell, whose replies to "Ooma behind switch" gave me the crucial boost I needed today.

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Re: Telo after switch + Cox Internet

Post by Troyjoy » Sun Jun 30, 2013 8:37 am

I thought it might help to offer a couple worth-a-thousand-words screenshots. These are on separate pages in the Surfboard admin interface. I included the guidance that appears on the DMZ page to help other newbs learn a bit about it like I did.
2) DMZ setting
Ooma-Config2DMZ-130629.png (37.5 KiB) Viewed 6328 times
1) Port Forwarding settings
Ooma-Config1Ports-130629.png (88.97 KiB) Viewed 6328 times

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Re: Telo after switch + Cox Internet

Post by dknyinva » Sun Jun 30, 2013 10:50 am

There are a couple of things you need to be aware of as they might be a security risk.

1. Putting a device in the DMZ exposed it to the Internet without any protection, so port forward is not necessary
2. If you decided not to put the device in the DMZ, then Ooma uses those ports for outbound traffic NOT inbound traffic. Meaning you shouldn't be using port forward at all, but configure your router to allow those ports open for outbound traffic.

"Ooma uses the following application ports for outbound data and voice traffic:

UDP 53, UDP 123, UDP 514, UDP 1194,UDP 3386, UDP 3480, UDP 10000-30000, TCP 110, TCP 53 and TCP 443.

This port information can be useful if you have a special network configuration with a firewall device upstream of the Ooma Hub or Telo that restricts application ports on the inside or "private side" of your network for outbound traffic. Firewalls are typically on by default for inbound traffic and no special modifications are required to allow that traffic through."

Good Luck

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Re: Telo after switch + Cox Internet

Post by highq » Sun Jun 30, 2013 1:49 pm

I have to concur.

I block all incoming connection protocols except smtp, ssh, http, ftp, and uucp. I have no incoming port forwarding whatsoever. And my Ooma Telo works perfectly well.

I have concluded that the Telo initiates every transaction: it has to be polling frequently (not only to initiate an outbound call, but also to latch on to an incoming call, or to learn that a software upgrade is ready). does not run any command to connect to anyone's Telo.
"... don't call us, we'll call you ..."

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Re: Telo after switch + Cox Internet

Post by beerman1957 » Mon Jul 01, 2013 8:40 am

This is an odd result. I have Cox and used the exact same Motorola Cox Router. (They recently switched to Cisco).

Here is what I had to do to get it to work.

Cox Cable Motorola ====> Cisco E4200 +======> OOMA on one port of Cisco E4200.

1. Disconnect all routers power.

2. Connect the Cox Router and wait for all lights to go green.

3. Connect the E4200 and wait about 30 Seconds.

4. Power up the OOMA.

I never had to set up anything else and this solution is 100% accurate for Cox Cable. Have you tried this set up? I found out the OOMA was confused on the DHCP due to the funky way the Surfboard decides on DHCP. I found this all out by asking the Cable Guy who said this was a common issue with VOIP phones and the SB Router.

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Re: Telo after switch + Cox Internet

Post by beerman1957 » Mon Jul 01, 2013 8:44 am

Since Cox gave me a new Cisco DPC3010, I no longer have to do magic Voodoo if my power goes out on the cable modem. I no longer have to do some weird order to get OOMA back up.

I do have UPS but we had a recent power outage over 4 hours and the UPS went flat. Still, the reboot was flawless once power was restored.

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