Hello everyone,
Are you one of the millions of people around the world who get their telephony service from their cable company? Or do you use some other type of VoIP service over your broadband connection? If you have any questions or comments on the technolgies used to make these services work I may be able to help.
I've recently authored a book entitled PacketCable Implementation. PacketCable is a project aimed at defining the specifications for delivering real-time multimedia services over a bidirectional cable plant. The initial phase of PacketCable, PacketCable 1.0, defines a complete architecture for providing primary line telephony over a cable plant. There are several components in the PacketCable 1.0 architecture such as the cable modem equipped with telephony support (otherwise known as the embedded Multimeda Terminal Adapter - eMTA), the cable modem termination system (CMTS), the call agent, the trunking gateway, and back-office operation support systems. A majority of VoIP over cable deployments utilize some or all of the aspects defined in the PacketCable architecture.
The functional areas covered in the PacketCable architecture include mechanisms for eMTA provisioning, call signaling, voice stream encoding and transport, dynamic QoS (DQoS) treatment over the DOCSIS cable plant, resource accounting, and security.
The next phase of PacketCable, PacketCable 1.5, contains enhancements to PacketCable 1.0 such as defining lawful intercept requirements and mechanisms to allow different VoIP networks to communicate.
Voice telephony services are just the starting ground for PacketCable. The PacketCable Multimedia (PCMM) framework defines the architecture for providing DQoS, resource accounting, and security for the generic type of multimedia application. PacketCable 2.0 provides guidelines on how these applications can make use of a PCMM. It also addresses topics such as cellular integration with cable, cross-platform integration, and the use of SIP based endpoints.
If you have any questions or comments relating to PacketCable and/or the equipment involved please let me know. Also if you would like to discuss a topic relating to the underlying technologies used in PacketCable such as the DOCSIS standard for enabling two-way IP communication over cable networks, please send me a note.
I look forward to hearing from you....
Jeff
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Packetcable
Hi jeff,
Recently, I was reading some articles in your book packetcable implementation, I would like to do some test with a Ethereal packet sniffer utility, and I got some questions for you.
1.- Is possible see the call flow with a PC running Ethereal connected to a eMTA?
2.- Winpcap is for windows?
3.- Libpcap is for linux?
Thanks a lot for your advance
PacketCable
Hi Carlos,
Thanks for reading my articles :-). So unfortunately, you aren't going to be able to see the call flow with a PC connected to the MTA. If you have telnet access to the eMTA there are typically debugs you can enable which will show the call flow - the actual syntax is going to depend on the eMTA vendor. Otherwise, you would need access to the CMTS or some device upstream from the eMTA.
To answer your other question winpcap and libpcap are used by Ethereal/Wireshark to do the packet sniffing and winpcap would be used for Windows whereas libpcap is for Unix/Linux.
Hope this helps,
Jeff