new toy to play with

[mbossman2]

just got my voice over vpn softphone up and running (it is a corporate thing, not exactly ready for home/consumer use, you need some special hardware).

Sounds better than many internet telephony products,& gives me full access to the features on my office phone (caller ID, voice mail, conference calling etc) but has a ways to go to match my office phone. its a little noisy and has a slight echo.

if you are up to reading, you can check out the technology here:

www.cisco.com/go/iptel

and the specific product at
http://www.cisco.com/en/US/products/sw/voicesw/ps1860/index.html

[Blakhart]

cool

[scott_d]

We have those IP phones at school. How do they work exactly? its prolly on cisco's site, but can some one just sum it up for me?

[Byte 2.0]

I need to read that. It is my understanding that is going t be offered for home use in some areas soon, and that I will be supporting it. Any info is helpful, thanks

[mbossman2]

Originally posted by scott_d
We have those IP phones at school. How do they work exactly? its prolly on cisco's site, but can some one just sum it up for me?

IP telephony is what I call an "end game" technology in the networking field. Switches and the embedded technology in them make all of this possible.

IP phones first take your voice conversation and digitize it via DSP's (digital signal processors: chips that take the analog voice pattern, chop it up and convert it into a string of 1's and 0's) and then, using ethernet and other networking protocols, packetizes the data and ships it out onto the network. Once on the network there are various components that move the packets around to the desired destination. I'll break those down one at a time:

Switches: these devices, be they layer2 or layer 3 switches, do several things: 1) they identify the traffic as voice traffic, 2) prioritize the voice packets over data packets (as voice is far more latency sensitive than say your email) and then does the switch thing and send the packets onto their destination:

IP Phones: as indicated above, the phones digitize and packetize your voice. In addition to that, the phones also tag the packets as either voice or "regular" data, using layer 2 and 3 tagging mechanisims built into the ethernet and IP headers.

Voice Gateways: These act as the connection out to the regular phone system. So these devices "depacketize" and de-digitize" the voice stream and push it out to the regular public phone system for the phone company to circuit switch the call to its destination. the process is reversed on an incoming call.

WAN Routers: these, in this design scenario, are and act no differently than plan old routers, giving you access to the corporate WAN (be it frame relay or point to point) and do nothing more than route the packets around the network. The only thing special they do is prioritize the voice packets ahead of the data packets.

Internet Routers: again, all they do is route traffic. They are, in my case with softphone, able to identify the voice packets and make sure that they are sent out onto the private network, with the appropriate tagging to prioritize them on the private LAN/WAN.

The final piece is what Cisco refers to as the Call Manager (CM).
CM is the telephone operator. It is a server running Win2K server and CM software. It is responsible for detecting when phones come off hook, sending dial tones, providing the network destination address for the call based on the #'s dialed and routing the call over to the voice mail system if the destination "rings" too many times. The CM is really only there for call set up and breakdown, once the call is in place and running, the CM does nothing to the call.

The reason that this is such a popular technology with businesses is the following:

1) using and leveraging an IT departments existing knowledge of Win2K and IP networking, allows them to breakaway from the proprietary systems that make up many PBX's. Most traditional PBX's have, in addition to the acquisition cost, very high monthly maintenance fees to maintain and upgrade the "core box".

2) in addition to the monthly maint. fees, the costs of making adds, moves and changes to the telephony network using traditional PBX's is astronomical. I have seen costs in excess of $600 to move a user from 1 cube to another while maintaining their same extension. With IP tel, all you have to do is have a network data jack, plug in the phone, let the phone boot up and the system "knows" where you are and will route calls to that device and location.

3) finally it cuts down the added costs of running 2 sets of wiriing. it better utilizes the, not insignificant, investment in you data network (DYK, most switched networks never get over 25% utilization, why not invest in technology that maximizes the use and ROI of that asset?).

Please understand that this is a VERY simple overview of how IP telephony works. Designing and implementing this, should really be left to the professionals for any installs of greater than 25-30 phones.

Byte,

this will be offered to the consumer user probably within the nect 12-18 months. The telco/SP will more than likely have a CM cluster set up at the CO and the rest of the phone network will very rapidly take on the look of a large, tiered layer 3 enterprise level network. If i were going to dive in from your perspective, I would become conversant with:

802.1p
Layer 2 and layer 3 tagging
multilayer switching (dependant on the manufacturer)
remote management of switches and routers.

there are many courses out there that focus on the design, implementation and support of IP voice networks, check with companies like Knowledgenet (or you local it training provider...look for someone higher end, specializing in Cisco or other high networking vendors training curriculum).

[Confused]

Company I retired from and where I do most of my contracting work for has been doing that for couple of years now. Works great. Of course it is much better in the corporate world with dedicated T1's and their own switches.

I'm not sure whether voice over IP or cell phones are going to be the dominant force that will replace the wired phones in private residences. But I do believe the days of the wired home for voice are numbered. Already I have a couple of friends with cable that no longer have a wired phone. They use cell phones for voice and cable for internet.
Chas

[mbossman2]

the big battle has yet to take place (it is close tho): who (or what) will provide you with: Voice, Video and data services into your home. Will it be the cable company, the phone company, a satellite/wireless company?

that battle will revolutionize the communication industry.

My guess is that the cable company will win because they have a private network just about everywhere that has sufficient capacity to handle all of the traffic. BUT their customer service leaves a lot to be desired (because they are so used to being a monopoly in their area) and that will definitely work against them.

Wireless will be cool, but the reliability and ubiquitous coverage is not there yet (ie, where I live, i have crappy coverage, but move 400 yards in any direction the coverage is perfect. there are 50+ families in this 1/4 mile radius circle who have unacceptable coverage and I know I am not alone).

The phone company is close, but they have to breakout of their circuit switch mentality and embrace, what is, the 1st revolutionary change in their industry since the decline of the switchboard operator.

I am betting that on the company that covers all 3 areas as the "big" winner.

[ffish]

I used to use IP telephony to contact friends, they are cheap,
or free for pc-to-pc calls, I know there are already a lot of ITSP(internet telephone service provider), check out http://www.iphone.shows.it for more.

[Confused]

Originally posted by mbossman2

My guess is that the cable company will win because they have a private network just about everywhere that has sufficient capacity to handle all of the traffic. BUT their customer service leaves a lot to be desired (because they are so used to being a monopoly in their area) and that will definitely work against them.

I agree. Their pay structure is also in their favor, at least for now here in Louisville. But their reliability and customer service nedds improvement. True story. They built a new house next door. I watched as backhoe operator cut the main cable feed while searching for sewer hookup. Customer service insisted that I check my TV and connections. I guess they have a script to go thru and there is no way of bypassing the process.

[/B][/QUOTE] The phone company is close, but they have to breakout of their circuit switch mentality and embrace, what is, the 1st revolutionary change in their industry since the decline of the switchboard operator. [/B][/QUOTE]

Their union pay structure and job classifications are also working against them.

I [/B][/QUOTE] am betting that on the company that covers all 3 areas as the "big" winner. [/B][/QUOTE]

Agree
Chas