We have a new fiber connection for our company that sports 100 Mbps and I'm looking to upgrade the existing router to handle the increased bandwidth. We currently have a Cisco 1841 that only will do about 35 Mbps. I'm a little familiar with routers but not enough to feel comfortable making the final decision (without asking) on what the best one would be to accommodate 100 Mbps and security. Our current configuration does aaa authentication easyVPN , crypto pki certicate, port forwarding and ACL lists.
I've looked at the 1941's and 2951's but I don't understand the difference between SEC/K9 and ISR enough to make a decision without some help.
Can anyone recommend a good Cisco router to replace the 1841 and maybe explain the differences of SEC/K9 and ISR?