Modem support VoIP
Modem passthrough over VoIP provides for the transport of modem signals through a packet network by using pulse code modulation (PCM)-encoded packets.
Modem passthrough performs the following functions:
* Repressing processing functions like compression, echo cancellation, high-pass filter, and voice activity detection (VAD)
* Issuing redundant packets to protect against random packet drops
* Providing static jitter buffers of 200 milliseconds (ms) to protect against clock skew
* Differentiating modem signals from voice and fax signals, indicating the detection of the modem signal across the connection, and placing the connection in a state that transports the signal across the network with the least distortion
If you are replacing an analog PSTN line with VOIP service, in addition to ordinary phones, there may be other devices that contain data modems that were using the PSTN line. Examples are: Tivo, POS Terminals, FAX machines, etc.
The problem is that the codecs used by VOIP ATAs are designed to compress voice, not the analog signals sent and received by modems. A second problem is if a non-compressing codec is used, the transmission will be very sensitve to network QoS, i.e. packet loss, jitter, and latency will be issues. To sucessfully use data modems over a VOIP connection you will need a minimum of:
* A non-compressing codec - ITU G.711 is the usual choice
* A very high quality network connection
SIP-based VoIP Cable Modem
Motorola today introduced the SIP-based SBV5100 series, a new addition to its suite of voice-enabled cable modems.
As part of the company's broadband telephony product suite, the SBV5100 series converges voice and data, on one network, in one product. Bundling multiple services in one unit will offer consumers an array of advanced voice services. The SBV5100 supports full-featured primary VoIP-based telephone service for up to two telephone lines that are terminated in two RJ-11 connectors.
- VoIP Cable Modem Telephony Design
The Texas Instruments (TI) LBT400DV is the first-generation VoIP Cable Modem Telephony
Reference Design that integrates TI’s Cable Broadband Communications
and Telogy technologies. This reference design supports both data communications and VoIP telephony.
The LBT400DV combines Texas Instruments powerful cable modem and DSP technology with
Telogy Networks’, a Texas Instruments company, Golden Gateway Voice-over-Internet Protocol embedded
communications software. The integrated Voice-over-IP solution contains circuitry for connecting
four telephones and providing many of the enhanced features of the circuit-switched network through
the cable television infrastructure.
- VOIP Modem offer Comcast
The Motorola SBV5220 is equipped with an integrated Lithium-ion battery back-up, which provides up to eight hours of battery back-up in the event of a power outage in the home. Comcast expects to offer the Motorola eMTA in the second half of 2006 to Comcast Digital Voice customers nationwide.
Part of Motorola's expansive portfolio of telephony products, the SBV5220 serves as a single device connecting customers to their digital voice and high-speed Internet services. The SBV5220 can power up to two phone lines in the home using standard RJ-11 connectors. The eMTA can connect to a computer through either a 10/100Base-T Ethernet or a USB data port.
Gateway Modem Router
Voice over Internet Protocol is the ability to make and receive voice phone calls over an IP based network. This includes a Local Area Network and a public IP network such as the Internet. The technology has been around for many years but mostly at big business level who used their large network capacity to also carry voice phone calls.
The NB9 MyNetGateway delivers an all-in one Integrated Access Device. It includes an ADSL2+ modem, 4-port Layer 3 Quality of Service (Qos) router, 2x FXS ports for VoIP equipment and1xFXO port for PSTN lifeline backup in one device! Now home, home office and small business users can eliminate the clutter of multiple Internet/networking devices and consolidate it one neat unit.
- VoIP cable modem - IP telephony products
The PCX3000 is a PacketCable-based VoIP cable modem that includes dual ports for telephone connectivity, in addition to USB and Ethernet interfaces for data connections. The modem is designed to meet Network Calling Signaling standards to ensure interoperability with all major cable broadband call systems. The modem also supports DOCSIS 1.1 specifications, which allow high-speed Internet services and tiered bandwidth options, as well as multimedia applications, such as video on
demand.-Toshiba America Information Systems.
- Motorola Takes SIP with VoIP Modem
Motorola will provide cable customers with a taste of the newer telecommunications technologies with its rollout of a
protocol modem based on Session Initiation Protocol (SIP). SIP has become a de facto standard for newer IP-communications services ranging from IP messaging to Internet telephony and hybrid cellular-Wi-Fi phone services now on the horizon.
Available toward the end of this year, the new SIP-based Motorola SBV5100-series modems will therefore offer cable operators a greater choice for applications they can layer on top of their high-speed-Internet and voice services, according to Motorola.
Zoom X5v ADSL VoIP Modem
The Zoom X5v Model 5565 integrates a full-rate ADSL modem, router, SPI firewall, four-port 10/100 Ethernet switch, USB port and VoIP phone port into one compact product. The Model 5565 comes with Global Village phone service for free VoIP to VoIP calling worldwide and money-saving connections to standard phones.
The X5v modem/router has a Local Phone port and intelligent relay that lets the same standard single-line phone be used for both conventional phone calls or Voice Over IP (VoIP) calls.
Because the X5v integrates Internet telephony with a full featured ADSL gateway, setup is easy and system security is ensured. The Model 5565 comes with free Global Village VoIP phone service that sets up in minutes and lets you simply dial phone numbers and make free calls to compatible devices anywhere in the world. And because the X5v uses SIP, the most popular protocol for voice communications over the Internet, you can tap into a rapidly-growing world of free and very low-cost phone services.
Modem Maker Launches VoIP Service
Twenty years ago, Boston, Mass.-based Zoom Telephonics was not known as the best modem maker in the business. Since then, the company has improved its own product line and managed to acquire two of the biggest names in modems: Hayes, founded by and named after the inventor of the modem, and Global Village, whose Macintosh modems were among the best.
Now that the company is launching a VoIP service, the less recognized Global Village brand seems idea for VoIP. "It's a neat name for a VoIP service," says Dean Panagopoulos, vice president of Zoom's network products group.
- VoIP Cable Modem Offerings
Motorola, Inc. expanded its family of voice-enabled cable modems with the introduction of the SBV5100 series. The new models, based on the Session Initiation Protocol (SIP), one of the more common voice and multimedia protocols in the telecommunications industry, provide greater choice to cable operators as they select the ideal technology for their systems.
With the pending emergence of PacketCable 2.0, which includes IP Multimedia Subsystem (IMS), many cable operators are adopting or evaluating SIP-based devices for their networks -- SIP is an emerging standard of choice for Inter-network communication.