NETWORK WORLD NEWSLETTER: CAROLYN DUFFY MARSAN'S ISP NEWS REPORT 11/03/04 Today's focus: Mailbag: Readers question performance for VoIP SLAs
Dear [EMAIL PROTECTED], In this issue: * AT&T explains how it bases VoIP quality on ITU's R-Factor * Links related to ISP News Report * Featured reader resource _______________________________________________________________ This newsletter is sponsored by NetScout The deployment of VoIP is well underway and unstoppable, but the implementation and ongoing support is extremely challenging. To successfully support VoIP and other demanding applications, IT organizations need to change their approach to network management. Learn about readiness assessment, design and ongoing management in the Network World Special Report: Recommendations for Implementing and Managing Converged Networks. http://www.fattail.com/redir/redirect.asp?CID=85920 _______________________________________________________________ NW TECHNOLOGY INSIDER: STORAGE ILM With real benefits in terms of saving money and making business run more smoothly, information lifecycle management deserves a closer look. In this in-depth technology review, we profile users who are on the cutting edge of ILM and describe how ILM can be one of the building blocks of the new data center. Click here: http://www.fattail.com/redir/redirect.asp?CID=86083 _______________________________________________________________ Today's focus: Mailbag: Readers question performance for VoIP SLAs By Carolyn Duffy Marsan We've received many insightful comments and questions from readers about our series on the service-level agreements offered by top-tier carriers. Today, I'll share a few thoughts from readers who are interested in IP network performance as it relates to emerging applications such as VoIP and interactive video. One reader had a follow-up question for AT&T about its SLAs, which were enhanced this fall. AT&T made several improvements to the SLAs for its IP network including guaranteeing 99.999% availability as well as reduced latency and quicker repairs. However, AT&T did not add jitter to its SLAs because a year ago it added a metric called R-Factor, which AT&T claims will measure the performance of VoIP applications better than jitter alone. One reader of the ISP News Report asked us for a full explanation of R-Factor. Here's what AT&T has to say: "In September 2003, AT&T introduced the industry's first global VoIP service-level guarantee for voice quality based on the International Telephone Union's (ITU) R-Factor standard. R-Factor determines voice quality based on a calculation of three combined network factors: latency (one-way transit across the network), packet loss (includes latency and lost packets) and jitter (the inter-arrival rate between voice packets)." Here are links to two network management vendors that have products to support ITU/ETSI's Standard R-Factor Passive QoS Test: Network Media <http://www.nwfusion.com/nlisp803> and Finisar: <http://www.elexo.fr/Fournisseurs/Finisar/Finisar.htm> Meanwhile, one reader shared the following thoughts about how SLAs will change with emerging applications such as VoIP: "I believe availability and bandwidth performance will continue to be the major factors [in SLAs]. However, as more and more subscribers are using their connections to support real-time applications (VoIP, interactive video, etc.), packet delay and jitter will become the important performance metrics that the ISPs will find difficult to assure. They are so used to blindly throwing bandwidth at problems. I am not sure how they will classify, police, shape and prioritize different traffic types when they do not own the network end-to-end." If you have an opinion you'd like to share about SLAs, here's your chance to speak out. Send us me an e-mail ( <mailto:[EMAIL PROTECTED]> ) and we'll print it in a future article. Or send us a question, and we'll chase down an answer. To read our series on the SLAs offered by top-tier ISPs, visit the following area of Network World's Web site: <http://www.nwfusion.com/newsletters/isp/index.html> _______________________________________________________________ To contact: Carolyn Duffy Marsan Carolyn Duffy Marsan is a senior editor with Network World and covers emerging Internet technologies and standards. Reach her at <mailto:[EMAIL PROTECTED]> _______________________________________________________________ This newsletter is sponsored by NetScout The deployment of VoIP is well underway and unstoppable, but the implementation and ongoing support is extremely challenging. To successfully support VoIP and other demanding applications, IT organizations need to change their approach to network management. Learn about readiness assessment, design and ongoing management in the Network World Special Report: Recommendations for Implementing and Managing Converged Networks. http://www.fattail.com/redir/redirect.asp?CID=85919 _______________________________________________________________ ARCHIVE LINKS Archive of the ISP News Report newsletter (formerly Internet Services): http://www.nwfusion.com/newsletters/isp/index.html _______________________________________________________________ FEATURED READER RESOURCE NW CLEAR CHOICE TESTS The Network World Lab Alliance is a coalition of industry experts, network integration consultants, independent test labs and universities who conduct single-product reviews and head-to-head comparative tests in real enterprise network settings. Find out which products get the "thumbs-up" in categories such as web front-end devices, WLAN security, anti-spam and more at: <http://www.nwfusion.com/reviews/> _______________________________________________________________ May We Send You a Free Print Subscription? You've got the technology snapshot of your choice delivered at your fingertips each day. Now, extend your knowledge by receiving 51 FREE issues to our print publication. Apply today at http://www.subscribenw.com/nl2 International subscribers click here: http://nww1.com/go/circ_promo.html _______________________________________________________________ SUBSCRIPTION SERVICES To subscribe or unsubscribe to any Network World e-mail newsletters, go to: <http://www.nwwsubscribe.com/Changes.aspx> To unsubscribe from promotional e-mail go to: <http://www.nwwsubscribe.com/Preferences.aspx> To change your e-mail address, go to: <http://www.nwwsubscribe.com/ChangeMail.aspx> Subscription questions? 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