[Winpcap-users] EXTERNAL: Limit on packet sending.

[Gianluca Varenni]

Pcap_send is synchronous, but it doesn't wait for the acknowledge on the network (which ACK, by the way?).
The reason why is slow is that you perform a system call per packet, which introduces latency and CPU load. As Michael correctly said, I would explore the use of pcap_queue's.

Have a nice day
GV

From: winpcap-users-bounces at winpcap.org [mailto:winpcap-users-bounces at winpcap.org] On Behalf Of Black, Michael (IS)
Sent: Wednesday, January 26, 2011 4:54 AM
To: winpcap-users at winpcap.org
Subject: Re: [Winpcap-users] EXTERNAL: Limit on packet sending.

I'll jump in here...somebody correct me if I'm wrong.

But...I believe pcap_send is synchronous so you're seeing network latency on the acknowledge.

You need to look at pcap_sendqueue.... functions.  Or just do the windows packet write without using winpcap at all.  Pcap is mainly for honoring timestamps which you probably don't care about.




Michael D. Black
Senior Scientist
NG Information Systems
Advanced Analytics Directorate

________________________________
From: winpcap-users-bounces at winpcap.org [winpcap-users-bounces at winpcap.org] on behalf of Akif Usman [akif.usman at hotmail.com]
Sent: Wednesday, January 26, 2011 5:46 AM
To: winpcap-users at winpcap.org
Subject: EXTERNAL:[Winpcap-users] Limit on packet sending.
HI,

I am experiencing a problem while writing a program that accepts packets from one ethernet interface puts them in a queue and sends it back to another interface. I am using threading to do this multitasking. The sending thread is very slow, i dont know why!

While i use threads and i receive at 50 Mbps i get a total forwarding rate of only 5-7 mbps. Then when i just grab one packet and keep on sending it in one thread (just to test the sending thread), it still gives me 5-10 Mbps . Is it a limitation of pcap_send packet?

I am using pcap_loop to receive packets if i want to receive them continuously. But i don;t understand why the sending speed is so low. Please help me i am stuck from quite many days on this.

Best Regards
Fika
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