Client connection

IMPORTANT: Use of the data exposed by these variables could, in some cases, introduce ossification risk to the internet.

client.as.name — Autonomous system (AS) name of the client
client.as.number — Autonomous system (AS) number of the client
client.identity — Identity for directors to determine which backend to pick
client.ip — Remote IP address of the client originating the client connection
client.port — Remote TCP port of the client originating the client connection
client.requests — Number of requests received on the current client connection, which may be longer lived
client.socket.congestion_algorithm — TCP congestion control algorithm for the client connection
client.socket.cwnd — TCP congestion window size (in number of segments) of the client connection
client.socket.nexthop — IP address of the next hop for the client connection
client.socket.pace — Ceiling rate for data sent to the client (kiB/s)
client.socket.ploss — Packet loss rate for the client connection associated with this request
client.socket.tcp_info — Indicates whether tcpi variables are available
client.socket.tcpi_advmss — Advertised maximum segment size (MSS) on the client connection
client.socket.tcpi_bytes_acked — Total number of bytes sent (and acknowledged) on the client connection
client.socket.tcpi_bytes_received — Total number of payload bytes received (and acknowledged) on the client connection
client.socket.tcpi_data_segs_in — Number of received TCP segments containing a positive-length data segment on the client connection
client.socket.tcpi_data_segs_out — Number of received TCP segments containing a positive-length data segment on the client connection
client.socket.tcpi_delivery_rate — Most recent application data rate measured on the client connection (bytes per second)
client.socket.tcpi_delta_retrans — Number of TCP retransmissions for the client connection associated with this request
client.socket.tcpi_last_data_sent — Time elapsed since the last sent packet on the client connection (ms)
client.socket.tcpi_max_pacing_rate — Maximum transmission rate in bytes per second on the client connection
client.socket.tcpi_min_rtt — Minimum round-trip time (RTT) observed on the client connection (µs)
client.socket.tcpi_notsent_bytes — Number of bytes in the write queue of the client connection that have not been sent yet
client.socket.tcpi_pacing_rate — Current transmission rate in bytes per second on the client connection
client.socket.tcpi_pmtu — Sender path maximum transmission unit (PMTU) on the client connection
client.socket.tcpi_rcv_mss — Perceived MSS of client TCP stack
client.socket.tcpi_rcv_rtt — Estimate of the time it would take to fill the current RWIN in microseconds (µs)
client.socket.tcpi_rcv_space — Number of bytes transferred to userspace over the previous RTT
client.socket.tcpi_rcv_ssthresh — Number of bytes advertised as the receive window on the client connection
client.socket.tcpi_reordering — TCP packet reordering retransmission threshold for the client connection
client.socket.tcpi_rtt — TCP smoothed round-trip time (RTT) for the client connection (µs)
client.socket.tcpi_rttvar — TCP round-trip time (RTT) variance for the client connection (µs)
client.socket.tcpi_segs_in — Total number of inbound TCP segments on the client connection
client.socket.tcpi_segs_out — Total number of outbound TCP segments on the client connection
client.socket.tcpi_snd_cwnd — Number of segments of the sender-side congestion window on the client connection
client.socket.tcpi_snd_mss — TCP sending maximum segment size for the client connection
client.socket.tcpi_snd_ssthresh — Number of segments of the sender-side slow-start threshold on the client connection
client.socket.tcpi_total_retrans — Number of TCP retransmissions for the client connection
fastly_info.edge.is_tls — Whether the client connection is over TLS
fastly_info.h2.stream_id — HTTP/2 stream ID
fastly_info.is_h2 — Whether the request was made using HTTP/2
fastly_info.is_h3 — Whether the request was made using HTTP/3
quic.cc.cwnd — Current congestion window
quic.cc.ssthresh — Current slow start threshold
quic.num_bytes.received — Total bytes received, at UDP datagram-level
quic.num_bytes.sent — Total bytes sent, at UDP datagram-level
quic.num_packets.ack_received — Total number of packets for which acknowledgements have been received
quic.num_packets.decryption_failed — Total number of packets that failed decryption
quic.num_packets.late_acked — Total number of packets for which acknowledgements were received after being marked lost
quic.num_packets.lost — Total number of packets lost
quic.num_packets.received — Total number of packets received
quic.num_packets.sent — Total number of packets sent
quic.rtt.latest — Value of the latest RTT sample
quic.rtt.minimum — Minimum RTT value, measured over the entire connection
quic.rtt.smoothed — Current smoothed RTT value
quic.rtt.variance — Current estimate of RTT variance
req.is_ipv6 — Whether the request is received over IPv6
req.is_ssl — Whether the request uses TLS
req.protocol — HTTP or HTTPS protocol of the request
tls.client.certificate.dn — Distinguished name of the client certificate
tls.client.certificate.is_cert_bad — Whether the client certificate is bad
tls.client.certificate.is_cert_expired — Whether the client certificate is expired
tls.client.certificate.is_cert_missing — Whether the client certificate is missing for mTLS
tls.client.certificate.is_cert_unknown — Whether the client certificate format is unknown
tls.client.certificate.is_unknown_ca — Whether the client certificate is issued by unknown CA
tls.client.certificate.is_verified — Whether the client certificate is verified successfully by mTLS
tls.client.certificate.issuer_dn — Distinguished name of the issuer of the client certificate
tls.client.certificate.not_after — End time of validity period of the client certificate
tls.client.certificate.not_before — Start time of validity period of the client certificate
tls.client.certificate.raw_certificate_b64 — A Base64 encoded string of PEM format x509 certificate from the client
tls.client.certificate.serial_number — Serial number of the client certificate
tls.client.cipher — Cipher suite used for the client connection
tls.client.ciphers_list — List of ciphers supported by the client (hex-encoded)
tls.client.ciphers_list_sha — SHA-1 hash of ciphers supported by the client (Base64-encoded)
tls.client.ciphers_list_txt — Text list of ciphers supported by the client (colon-delimited)
tls.client.ciphers_sha — SHA hash of cipher suite identifiers (Base64-encoded)
tls.client.handshake_sent_bytes — Number of bytes sent to the client during TLS handshake
tls.client.iana_chosen_cipher_id — IANA ID of the cipher suite used for the client connection
tls.client.ja3_md5 — MD5 hash of JA3 computed from client hello (hex-encoded)
tls.client.ja4 — JA4 computed from client hello
tls.client.protocol — TLS protocol version for the client connection
tls.client.servername — SNI server name forwarded by the client
tls.client.tlsexts_list — Numeric list of TLS extension identifiers (hex-encoded)
tls.client.tlsexts_list_sha — SHA-1 hash of TLS extension identifiers (Base64-encoded)
tls.client.tlsexts_list_txt — Text list of TLS extension identifiers (colon-delimited)
tls.client.tlsexts_sha — SHA hash of TLS extension identifiers (Base64-encoded)
transport.bw_estimate — Estimation of the bandwidth (bytes per second)
transport.type — Transport type

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