[asterisk-ss7] using dahdi as an E1 sniffer

Horacio J. Peña horape at compendium.com.ar
Fri Apr 30 10:58:02 CDT 2010


Is there any app that would allow two E1s to be "bridged" so I can
intercept a link and use dahdi pcap to analyze the traffic? (does dahdi
pcap work for audio/pri channels or only ss7?)

If there isn't, would something like this work?

int fds[64];

// open channels as rw, E1 1 in fds[0..31], E1 2 in fds[32..63]

int BS = 1;
char buf[BS];

while (read (fds[0], buf, BS) {
  write (fds[32], buf, BS);
  for (i=1;i<64;++i) {
    read (fds[i], buf, BS);
    write (fds[(i+32)%64], buf, BS);

(this uses fds[0] as clocking)

How many bytes at once (BS) should I read/write? Should I do something
very different? (It has been a long time since I worked with zap cards)

Horacio J. Peña
horape at compendium.com.ar
horape at uninet.edu

More information about the asterisk-ss7 mailing list