I have a site-to-site VPN b/ my HQ and my remote branch and I am facing slowness in VPN big time when synching emails through MS Outlook, however when connecting through remote VPN the users are not facing this slowness and are synching emails just fine.
I know IPSec adds overhead over IP traffic which is about 56 bytes, please correct if I am wrong. Now does Site-to-site VPN add more overhead than what the remote VPN adds causing this slowness? Or could that be due to wrong site-to-site VPN between the PIX and the remote branch's VPN device? By the way, for remote users VPN I am currently using Microsoft VPN.
Thanks for your question. Unfortunately, Your question is not related to the topic being covered, which is Physical Securtiy & Video Surveillance. Sorry for the confusion we may have created between Physical and Data security.
The nature of your question requires some indepth remote VPN expertise. My suggestion is to drop an email to Cisco Support: email@example.com
as a problem isolation session, you may exclude the smtp from the interesting traffic in your access-list, at both end. See if you expereince the same level of slowness. This would isolate the possibility of congestion at your WAN, as well as, a QoS policy might have been applied to limit the bandwidth allocated for email/smtp.