Dear folks, Thank you for your kind comment about IOS 12.0(7)S. I got a lot of response from nanog-pals. :-) According to that comment and Cisco's recommend, we will try another IOS version, 12.0(5)T1. Currently we have Cisco 7507 and 2 physical HSSI interface (one is VIP2 module), 3 HSSI software interface (because of VIP2 module). And we put the PA-2T3+ card on Cisco 7507 for another connection. Problem is that PA-2T3+ can be recognized only by 11.1.(?)CC, 12.0(?)T, or 12.0(?)S version. Cisco guy said that 12.0(?)S version is too early. So we will try 12.0(5)T1 on monday morning. Our Cisco 7507 has one RSP4 card with 256MB RAM. Is there anyone have experience with 12.0(5)T1? Is it stable? If it is not stable, we have only one option remaining, 11.1(?)CC. Please tell me your experiences. Basically we will try to turn off "ip cef" and "ip route-cache" option, too. I appreciate your comment. Thanks in advance. Hyun ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Hyunseog Ryu Network Engineer/Applications Engineering Norlight Telecommunications, Inc. 275 North Corporate Drive Brookfield, WI 53045-5818 Tel. +1.262.792.7965 Fax. +1.262.792.7733