Title: Nortel Networks Updated Statement about IPR claimed in RFC 3489 Date: 20 February 2008 Dear Sir, As identified in its IPR disclosure ID#918, Nortel Networks Limited has an issued US patent no. 6,993,595, entitled "Address Translation Change Identification", that may be relevant to at least a portion of this proposed IETF RFC 3489 standard if approved and implemented: Title: STUN - Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs) Tag: RFC 3489 http://www.ietf.org/rfc/rfc3489.txt?number=3489 As understood, RFC3489 is identified as a proposed standard but will be obseleted by the proposed IETF Internet draft-ietf-behave-rfc3489bis-13, Session Traversal Utilities for (NAT) (STUN), if such draft is approved as the resulting IETF standard. However, if and to the extent claims of U.S. patent no. 6,993,595 cover and are necessary to practice the resulting IETF RFC 3489 standard as approved, further to Nortel Networks Statement IPR ID#918, Nortel Networks is willing to make available licenses on fair, reasonable, reciprocal, and non-discriminatory terms under such necessary claims of this patent for compliance with the resulting approved IETF RFC 3489 standard. It is understood that if the IETF RFC3489 standard is withdrawn or obsolete, Nortel has no obligation to license a party requesting a license to such patent with respect to RFC3489 after it is withdrawn or obsoleted. Requests may be addressed to: Mark Hearn Nortel Networks 2221 Lakeside Boulevard, M/S 991/14/B20 Richardson, Texas 75082 USA hearnm@nortel.com My contact information is set out below. Kind Regards, Michelle Lee IP Counsel Nortel Networks Limited 5-195 The West Mall Toronto, Ontario Canada M9C 5K1 Fax: 905-863-1986 mleelaw@nortel.com