Hi,
Thank you for your post.
As far as I know, you may configure the ISA server to treat the traffic as local. Please perform the following steps:
1. Open ISA server, and navigate to Configuration, then click Networks.
2. In the center of the page near the bottom will come up a list of networks. Double Click on Internal
3. Click the “Domains” Tab. Click the Add button and Add access.sabre.com and hsspconfig.sabre.com.
[Note: If the user will be using other systems such as TSTS or CERT it may be wise to add them. Examples are decs.sabre.com, fos.sabre.com, tsts.sabre.com, frt.sabre.com, cert.sabre.com]
4. Click “OK” when done.
Regards,
Nick Gu - MSFT