In general, you will use HTTP (or secure HTTP) calls to transmit information between BizTalk servers in different organizations. So there really should not be any particular issues with ISA. (If you want to do secure inbound calls you will have to have a certificate. There is information on the ISAServer.org site about how to set this up.) There is an issue with ISA 2000 when you try to transmit a document of size >10K but this is fixed by SP1, so be sure to apply that. Guinn Unger -----Original Message----- From: nperez@xxxxxxxxxxxxxxx [mailto:nperez@xxxxxxxxxxxxxxx] Sent: Wednesday, July 14, 2004 6:07 PM To: [ISAserver.org Discussion List] Subject: [isalist] BizTalk 2004 and ISA http://www.ISAserver.org My company is in the early stages of planning out our Biztalk 2004 implementation. One of the things that we want to do is to connect to clients' Biztalk servers. Is there any documentation on how to configure ISA to connect to "outside" BizTalk servers and allowing "outside" servers to talk to the "inside" BizTalk servers? Anything on ISA in relation to BizTalk would be greatly appreciated. Thx!