Invalid LAPB frames

"RADHIKA LAHANKAR, BLOOMBERG/ 499 PARK" <[email protected]> Mon, 10 Nov 2003 09:51:36 -0500

Newsgroups	gmane.network.ethereal.documentation
Message-ID	<2960_2158_1068475896_931@inet3-p057>

Hi,
 I am trying to sniff the traffic on some routers. But ethereal is not able to 
display the frames correctly. It says

  DCE(Source) DTE (Destination) LAPB (protocol) and Invalid LAPB frame (Info).
What's the matter?
    Thanks - Radhika