From bd25a60d18a373b1cb686ef6d38a202ca642606d Mon Sep 17 00:00:00 2001 From: Larry Peterson Date: Fri, 19 Jun 2026 10:45:12 -0700 Subject: [PATCH] tweaks Signed-off-by: Larry Peterson --- overlay/design.rst | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/overlay/design.rst b/overlay/design.rst index be4e39b..1b86cdb 100644 --- a/overlay/design.rst +++ b/overlay/design.rst @@ -8,8 +8,8 @@ the new feature to the existing network? There are as many answers as there are overlays, but they all boil down to one pragmatic consideration: it is difficult to add new functionality to an operational network. The challenge of getting everyone to agree to -such an upgrade, let alone dealing with the logistics of deploying the -upgrade across thousand of switches, is an extremely high barrier. +such a change, let alone dealing with the logistics of deploying the +upgrade across thousands of switches, is an extremely high barrier. Demonstrating the value of a new feature is easier if you can run the new network *over the top*, without having to modify any of the existing network infrastructure. @@ -26,7 +26,7 @@ in a phenomenon that Clayton Christensen famously called the *Innovator's Dilemma*. Fortunately, networking gives us a workaround, with overlays being the widely accepted as a way to introduce disruptive technology. A National Academies report made this -observation about the state of the Internet over two decades ago: +observation about the Internet over two decades ago: *The existing core IP network could be used simply as a data transport service, and disruptive technology could be implemented as @@ -83,11 +83,16 @@ is little appetite for augmenting routers with storage. As we will see in Section |Overlay|.2, however, CDNs do include a "request routing" function, which has been proposed as a "content-based addressing" extension to the Internet's forwarding mechanism. But the success of -CDNs in providing the same service as an overlay renders this issue -moot. +CDNs in providing the same service as an overlay has made this a tough +sell. The ease of deploying any new feature in an overlay means you +need a compelling argument for instead adding that feature to the +core. .. TODO -- some might see this as dismissive of content networking - research, we could consider a sidebar (or not) + research, we could consider a sidebar (or not). + + I softened the language, and added a bit more about the bar being + raised. --llp The second example, video conferencing, supports a *multicast* function, whereby packets are delivered to multiple end-points instead