Larry: When do you see a timeframe for a drop dead date to convert from IPv4 to IPv6? Similar to the changes to DTV in 2009? Good question. We have already passed about three "drop dead dates" that were predicted. I personally don't believe there is one. Mandates have been tried, and so far have had limited impact. I believe IPv6 will be adopted when there are great reasons to. For example, NTT in Japan is using IPv6 for their broadcast HDTV system backbone because they have found the multicast capabilities of IPV6 to be superior to IPv4. So the need for a solution to a problem drove the technology. Not the other way around.
Abc: What technique would you suggest on worm mitigation control? There isn't one technique, you really need to think of it as a comprehensive plan. First, endpoint security: make sure to protect laptops and computers with anti-virus, anti-sypware, and anomaly detection software. Second, infrastructure protection: put controls in your network like Control Plane Policing (CoPP) and QoS Scavenger Class to protect during an outbreak. Third, visibility: turn on and "operation-ize" tools in your network like Netflow to become familiar with "normal" behavior so that you can see when a worm may be affecting your network. There is a good discussion in the QoS System Reference Network Design (SRND), by the way, on worm mitigation with QoS.
Moderator-Keith: Pre-submitted question: I need to setup a voice lab. Where can I go to get configuration examples, step by step instructions and network diagrams? The best practices designs for Cisco Unified Communications, including voice, are available on cisco.com at the SRND website. Just type www.cisco.com/go/srnd to see all of them. Then select Unified Communications. You will see best practices design guides dependent on which CallManager release you are using (6.0 is latest), and many other design guides for IP Contact Center, Wireless VoWLAN, etc.
PhilB: What's your opinion of Skype? A loaded question ... LOL ... my answer would be: for what application? Residential/consumer? Business? For residential use, I think Skype is a very interesting technology. What struck me most about it was how umpteen million people downloaded and starting using it (prior to the eBay purchase of it) without any advertising ... pure viral marketing and word of mouth. I like the innovations in Skype, that they challenged the norm and came up with a pretty good peer-to-peer technology. For business use, that's another story. It's probably not ready for that and also more importantly lacks some of the integration. VoIP is just one form of media. Video, collaboration, IM, app sharing are others that all need to be integrated with VoIP in the business app environment that we call Unified Communications.
Moderator-Keith: Pre-submitted question: Can you please provide me with details on where I can learn about VoIP, VoIP troubleshooting scenarios and VoIP Monitoring tools? Again, I highly recommend taking a look at the SRNDs for Unified Communications. As far as troubleshooting and monitoring, it depends what you want to monitor. If you are interested in monitoring VoIP quality, take a look at IP SLA (service level assurance). It allows you to script network probes to measure latency, jitter, and loss so that you can see the kind of performance you are getting on the network between different points.
TomSmall: What is the status of VoIP reliability, and how can I assure clients that it will be able to fully function with telephone and data connections? VoIP reliability has come a long way and many Fortune 5000 companies are changing over to the technology for their corporate phone communications. In terms of assuring service levels, I would say three things are critical: 1. Network reliability - make sure the network is designed for high availability AND fast sub-second failure convergence in the event of an outage. 2. QoS and service policies - make sure that even where bandwidth is plentiful, QoS will step in and protect the voice app if congestion occurs, and 3. Security - if your network is compromised, all apps including voice will be affected if you do not have a good mitigation plan. All that taken into account, the VoIP revolution is here to stay and the benefits in terms of flexibility and integration with other applications for collaboration outnumber the increasingly rarer outages.
Dslguy: Is there a Cisco reference Web site for setting up a CCNA lab? Moderator-Julie: Network World has a resource for you on that. Check it out here. We've had lots of questions today about Cisco Certs, so want to point out a resource on Network World's Cisco Subnet site for answers, Wendell Odom's Cisco Cert blog. He wrote a series on CCNA lab for instance, and is happy to answer other questions posted to his blog.
RodneyM: Are you a believer that the Internet will collapse by 2011, as published in recent news reports? Would restricting sites such as YouTube be a way to get a rational use of the Internet? I don't personally believe that will happen. We have done some interesting studies on forecast traffic loads in the future that even surprised us. The forecasts for video traffic are astounding. But I believe these are opportunities and challenges that ISPs and others will rise to. The Internet is about to undergo a major "next wave" of collaboration and information sharing. If you think about it, there used to be significant barriers to producing and publishing a video. Now, the barriers are all removed. Anyone can shoot a video and publish it. That leads to tremendous applications and information sharing I personally think have only just begun. But collapse the Internet? No...I don't believe it.
Moderator-Keith: Pre-submitted question: What should be the primary security concern of a network designer in riding voice over data? It's hard to pinpoint a single concern, but I would have to say the top issue is how do you secure voice without over-restricting data. In other words, it takes a balance of security when you integrate voice and data on the same network. There is an excellent discussion in this paper on Securing Voice. It's a chapter in the SRND I mentioned earlier on Unified Communications. Here's a direct link to the chapter.