This indicates an attack attempt to exploit a Denial of Service vulnerability in Ekiga.
The vulnerability is due to an input validation error in the SIP protocol when handling a malformed URI. A remote attacker may be able to exploit this to cause a denial of service condition on the affected system via a crafted request.
Ekiga 2.0.5 and earlier versions
Denial of Service: Remote attackers can crash vulnerable systems.
Apply the most recent upgrade or patch from the vendor.