Methods and systems to estimate encrypted multi-path TCP (MPTCP) network traffic include restricting traffic in a first direction (e.g., uplink) to a single path, and estimating traffic of multiple subflows of a second direction (e.g., downlink) based on traffic over the single path of the first direction. The estimating may be based on, without limitation, acknowledgment information of the single path, a sequence of acknowledgment numbers of the single path, an unencrypted initial packet sent over the single path as part of a secure tunnel setup procedure, TCP header information of the unencrypted initial packet (e.g., sequence number, acknowledgment packet, and/or acknowledgment packet length), and/or metadata of packets of the single path (e.g., regarding cryptographic algorithms, Diffie-Helman groups, and/or certificate related data).