Hi, I counted number of sending packet in code and wireshark.
I send 400Bytes packet, but wireshark packet be shown about 1500Bytes. While coded counter shows about 50,000 packets (data packet), wireshark captured 450,000 packets. I expected one send() be represented one packet at wireshark. Why does number of packet shown in wireshark is differ from transmitted packets ? Thanks for your help. 2016-04-14 15:20 GMT+09:00 Laur Joost <darem...@gmail.com>: > While UDP gives no order guarantee, the USRP still sends them out in > order. The uncertainty comes in cases where routing happens between the > USRP and the host. Still, within a LAN you can expect with relative > certainty, that packets will still arrive in order, as there is usually > only one route from device to host. > > 1. The sequence of the packets is important. It would be rather bad if two > bunches of samples in your IQ stream suddenly switched places. > 2. The host PC network stack does no reordering. It can't, by definition > of UDP, as there's nothing to reorder by. > 3. AFAIK, the UHD also does no reordering. However, the packets arriving > from the USRP __are__ numbered. If UHD detects a missing packet, it* prints > a D (to signify a Dropped packet) to stdout, and emits a new rx_time tag > for the next packet. > > * Actually, I don't know whether that's UHD or gr-uhd that does this. > > Hope it helped > Laur > > 2016-04-14 8:41 GMT+03:00 SangHyuk Kim <tkdgur7...@gmail.com>: > >> Hi all, >> >> I'm wondering about packet sequence. >> >> USRP sends UDP packets which is result of sampling to host PC. >> >> >> UDP packets tend to be out-of-order at high speed. >> >> My question is: >> - When USRP sends UDP packet high speed to host PC, the sequence of these >> packets is important ? >> - Do host PC reorder these packet ? (Do PC waits for certain packet ?) >> >> Thanks. >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >
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