What tool and process are you going to use in order to remain undetected by an IDS while pivoting and passing traffic over a server you've compromised and gained root access to?

Telnet transmits all data in cleartext with no encryption, which would make the traffic more visible and inspectable by an IDS, not less.

Cryptcat is an enhanced version of netcat that incorporates Twofish symmetric encryption for all transmitted data, making the payload opaque to signature-based IDS inspection. Because the traffic is encrypted end-to-end between the compromised server and the attacker, the IDS cannot match known malicious patterns or read the content of the pivoted session. This is a standard post-exploitation technique covered in CEH and offensive security curricula.

Using HTTP does not encrypt traffic; IDS systems routinely inspect HTTP content and can detect malicious payloads or anomalous behavior within HTTP sessions.

Alternate Data Streams is an NTFS file system feature on Windows used to hide data inside files - it has no mechanism to conceal or encrypt outgoing network packets, and this scenario involves a CentOS (Linux) server where NTFS does not exist.