Hi Sergio, Thanks for the reply. Let me explain it better.
HDBaseT is a protocol developed by Valens LTD. This protocol is used mainly for extenders. There is an RX chip and a TX chip. The protocol is transferring video, audio, USB, RS232, IR and ETH over CAT5/6 cables !. As HDMI or other video connections are limited in cable length. If you go above 5-10m cables are very expensive and without active cables you have a problem getting longer cables. HDBT is designed for 100M :-) Anyway, HDBT devices use a regular CAT5/6 ETH cable to transfer all the above with one cable and with minimum loos in video quality. What is my problem?. I am working on systems that have one or more HDBT TX or RX. An average system has an embedded ETH switch that has one or more outputs that are connected to an HDBT chip (local). This chip is transferring the ETH data to the remote chip over CAT5 cable. There is indication for HDBT link (between HDBT TX <> RX) but there is no indication on remote side ETH link. The local system with the embedded ETH switch has an internal micro that runs HTTP server etc... Normally the device will be connected to the network. That means that the system itself has an ETH connector connected to the network and on the other end (internal) it is connected to one of the embedded ETH switch ports. The micro has access to this port and to the local ETH switch. Our client is asking that if we connect the remote ETH side (over HDBT) to a router or network to be able get a dynamic address and operate the same as if we connected the local ETH system port to the network. Without some indication if there is an ETH link on remote side I cannot do that. What we did in one system is that we added code to the micro on the remote HDBT end to detect ETH link. ETH link status was sent as a command over the serial connection that the HDBT transfers as well. I am wondering if there is an elegant way of doing it without sending an explicit status to the local system >From the remote side. I hope now it is clear :-) BR, Noam. -----Original Message----- From: lwip-users [mailto:[email protected]] On Behalf Of Sergio R. Caprile Sent: Wednesday, November 09, 2016 4:32 PM To: [email protected] Subject: Re: [lwip-users] elegant way to detect network connection Hi Noam, I was about to say you could sniff how windows 7+ does it; but I don't think they would do it in an elegant, not even standard, way... ;^) I don't know if I get the whole picture, but I bet your problem is an "application ping". Do you actually need to know link is present or another device like yours or server or @ access or ? Yes, ICMP Echo Requests might be discarded by the router, I think it is a bad idea on an internal network, but some admins think otherwise. That is why I suggest "application ping", as long as your devices can see each other, you know you have a link. It is usually done on a separate UDP port, but some guys like to dedicate in-band commands to that purpose, like a keep-alive message. What I suggest is sort of a discovery protocol on UDP broadcasts, or a directed app ping if you know your neighbors addresses. Toying with your DHCP server every half a second might pester some net admins and get you enemies for free... I wouldn't go that way, I think your application's problems have to be solved by your application. Just my 2 cents. Regards! _______________________________________________ lwip-users mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/lwip-users _______________________________________________ lwip-users mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/lwip-users
