The resulting transparent connection allows the same access as if the machine were being used locally. Once the Cisco CallManager at your site accepts the password, the Telnet client running at the Cisco TAC connects to the Telnet daemon running behind your firewall.
Note The Telnet client at the Cisco TAC runs in compliance with systems running on Windows NT and Windows 2000, or with UNIX operating systems. Using this relay server maintains the integrity of both firewalls while supporting secure communication between the shielded remote systems. Using an external proxy machine, the system relays TCP/IP communications from behind your firewall to a host behind another firewall at the Cisco Technical Assistance Center (TAC).
These applications protect your network by restricting IP connections between the network and the public internet.įirewalls work by automatically blocking TCP/IP connections initiated from the outside, unless the software is reconfigured to allow such access.Ĭorporate networks normally permit communication with the public Internet, but only if connections directed to outside hosts originate from inside the firewall.Ĭisco Secure Telnet takes advantage of the fact that Telnet connections can easily be initiated from behind a firewall. Virtually all internal networks use firewall applications to restrict outside access to internal host systems. Using Telnet directly can establish a TCP/IP connection, but it requires opening your firewall, which can compromise security and cause delays in service. These paragraphs describe each component and application, along with a scenario outlining how you can use them.ĬSEs can use techniques other than Cisco Secure Telnet to provide remote connectivity to a customer site, but using other methods may impose unacceptable conditions.ĭial-in access requires installation of a dedicated phone line and modem at your site, so dial-in access may be impractical.
The Cisco Secure Telnet system design provides the basis for communication with any Cisco CallManager installations on your site. You must provide a network administrator at your site to help initiate the process. Note Cisco accesses your network only with your permission. This secure connection allows remote monitoring and maintenance of your Cisco CallManager servers without requiring firewall modifications. This chapter provides a description and overview of Cisco Secure Telnet and contains the following topics:Ĭisco Secure Telnet offers Cisco Service Engineers (CSE) transparent firewall access to Cisco CallManager servers on your site.Ĭisco Secure Telnet works by enabling a Telnet client inside the Cisco Systems firewall to connect to a Telnet daemon behind your firewall.