> -----Original Message----- > From: [email protected] [mailto:juniper-nsp- > [email protected]] On Behalf Of Martin T > Sent: Monday, April 04, 2011 11:38 AM > To: [email protected] > Cc: [email protected] > Subject: Re: [j-nsp] Juniper "firewall policer" inner workings > > Packet loss, which Iperf rapports, boils down to how the > "bandwidth-limit" and "burst-size-limit" works. As Stefan mentioned, > it would be logical that everything below IP header is counted into > this "10m" as policer is under family inet. If so, the packet loss > should be 8 bytes per packet because the UDP datagrams Iperf send out > are following(checked this with tcpdump):
Actually, what I'm saying is that it also includes the IP Header as well, so it should be 28 Bytes per packet. > Iperf sends packets with 1470 byte payload. In addition, there is a 8 > byte UDP header and 20 byte IPv4 header. So according to tcpdump the > whole IPv4 packet is 1498 bytes. > > However, if 51020 UDP datagrams were sent during the test, it would do > (51021*8)/(1024*1024)=0.40MB lost data, but according to Iperf, the > dividing between the sent and received data is 1.7MB. See above. > However, as increasing the "burst-size-limit", the packet loss > decreases.. This doesn't surprise me, you've given a larger buffer to smooth things out... Stefan Fouant, CISSP, JNCIEx2 www.shortestpathfirst.net GPG Key ID: 0xB4C956EC _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
