[havkom]

The most compatible technique is long polling (with a re-established connection after X seconds if no event). Works suprisingly well in many cases and is not blocket by any proxies.

[bullen]

long-polling are blocked to almost exactly the same extent as comet-stream and SSE. The only thing you have to do is to push more data on the response so that the proxy is forced to flush the response!

Since IE7 is no longer used we can bury long-polling for good.

[notreallyserio]

How much more data do you have to send? Is it small enough you aren't concerned about impacting user traffic quotas?

[bullen]

Just enough to trigger the buffer... 1024-8192 bytes or something like that... a fart in space since it's just once per session!

[mst]

Reminds me of needing to do similar things to convince browsers to render e.g. a custom 404 response.

Mildly annoying, but hardly onerous.