VPN routers, and tie-lines??

[FMROB]

Okay,

Here is a really stupid question. I, not knowing much about routers, internet, ethernet, etc. am trying to learn as much as I can aobut it.

One guy once told me in conversation that it would be possible to create a "T-1" style connection using two VPN routers at differenet locations via the inernet (cablevision).

I know that VoIP has been kicked around here, and I know that there are many expensive products on the market to this. But, it is very, very, very cheap technology that they are trying to capitilize on. So I am trying to re-invent the wheel here.

Our need would be for remote rx's, base station control, and possibly to run another repeater distant to the main unit.

Here are my questions.

1) Is this possible with a VPN router.

2) If I were to use two of these http://www.engageinc.com/applications/pbx_iptube.html

How would I derive a way to connect the actual copper connections to the unit? In other words if I had the doug hall voter on one end, and a RX radio on the other end and two of these units, what elese would I need?

I know that steve makes such a unit, but we are looking to do this without computers involved, just the units itself and a cable modem connection.


Thanks, Rob

[tvsjr]

What is the purpose of this system? Is it going to be used in mission-critical applications?

If so, doing VoIP across VPN is a Bad Idea. You have no way to use QoS (quality of service) to prioritize voice packets across the public Internet... if a link somewhere gets loaded down, poof... you lose connectivity.

VoIP linking for voters (like we're about to do with some JPS voters) is generally used when you're doing a point-to-point wireless ethernet shot. In general, it's significantly cheaper to make a 100Mbps Ethernet shot with commodity equipment (preferably on the licensed 4.9 band) than it is to make a T1 shot. Plus, you can assure QoS and run other stuff across the link if needed.

[FMROB]

No, It is not for a mission critical system.

Our distance is too great for a micro hop, so the internt will serve our purpose cheaply, as both locations have broadband connections.

Any other insight into this, as you said that you are doing something similar.

Do guys perfer the doug hall voters, motorola, or JPS units?

We have worked with moto, and doug hall and found the doug hallto be easy to use, and work very well.

Thanks, Rob

P.S. We are really lookig for more info in the IP tube stuff, or emulating a t1 backhaul over the internet.

Also, How would one prioritize packetts to avoid loosing data transfer.

[ve3nsv]

Are you just looking to link two radios together at each end? If so you could use two IP-223's from Telex or Critical RF's solution for linking over regular internet connections.

[psapengineer]

RoIP Radio over IP

The "IP Tube" device you mention is designed to carry a full T1 (24 voice channels) using IP protocol (Internet Protocol).

Then, on the T1 side of the device, you need a T1 shelf to break the T1 into it's 24 channels. You might go e-bay and search on "Telco Systems" and use the " " to force the search to be specific. This will yeild examples of T1 shelves.

If you're only interested in one voice grade circuit you might look at the NXU-2 from JPS Communications. It is an interface that does Tx Audio, Rx Audio, PTT, and COR conversion to IP.

Lastly, a word of caution, there are two things to condiser when using IP to do transport of voice grade information, Bandwidth and Latency. Latency is the time it takes the packet to propogate through the internet route. For most internet connections in the real world both latency and bandwidth vary by time; they are not stable.

The IP tube needs at least a full 1.5MB/sec. The NXU-2 needs about 64KB/sec. Both need reasonable latency.

If you're using the system with a voter, as you mentioned, latency is an issue. The voter is expecting all audio to arrive at its inputs at the same time at it's inputs; not a few tenths of a second late on one of them; it need to compare "like" audio signals.

You might also need to speak with your ISPs (two ends) to verify that the system can support QOS/TOS so that you and use the IP-Tube or NXU-2 to add a "voice priority" bit to the packet; this should help with latnecy when the internet is in heavy use.

Good luck, Bob

[/\/\y 2 cents]

Do not use the iP tube from engage. Mark Doyle and Tom Verpluge sold me these and they do not work. I bought (2) DLT-1C to resell to link a system and they did not work at all. He would not give me the money back and I lost $8000:( because the units had compression and were more expensive. That is the price I paid for being on the cutting edge and starting a company based around this. They will work if you have Gigabit ethernet, MPLS etc. But not over a regular connection (DSL,Cable, BPL, etc.) and that is where you save the money and is the compelling reason to switch to iP. I am now offering another makers units OEM'd for me that DO work (I have plenty of references to prove it) and we have linked iDEN base stations back to ISC's over Wild blue Satellite internet from NRTC in Reston Va just to talk about one of the more exotic installations. I also have many happy passport owners saving over $16,000 a month on t1 backhaul and banding together their regional systems to launch a missle at nExTel. If you want to take our gear for a spin just let me know.

On the other note: The only units we have that use a PC are our SiteCAST which links a single repeater, simplex base or talkgroup. The PackeTUBE does 24 or 31 DS0 channels, allowing you to helix up all of the repeaters and control signalling of the system and replace the copper channelized T1 span. Sub-audible signalling is no-problem. All of the electrical levels are pristine from A/D-->D/A Please visit us at IWCE this year in the booth, we will have live systems up and running. I am trying to also have a Segway at the front door of the convention center leading tours back to our booth every 30 minutes or so.

Speaking of NXU-2, I also have some NXU-2 units for sale that we took apart to see how they tick and dont need them anymore. They really didn't do anything other than connect site A to Site B without a multicast WAN address, which no ISP gives out. Plus, they were UDP which means that you never know if your call was delivered to the other site because there is no error correction/connectionless protocol. Pretty uninspiring if you ask me. Let me know if anybody wants em'

Steve

[FMROB]

Steve,

I need then to get back into contact with you. I would like to purchase two of your units. Thanks, Rob


P.S. I lost you info in a CPU crash a while back, so I don't have your ## anymore.