1.xx - ERR_READ_TIMEOUT (Generally the HTTP request/response timed out when Akamai tried fetching content from origin. Default read timeout is 120s)
3.xx - ERR_READ_ERROR (Generally the TCP connection from Akamai to origin was successful but the origin did not send any (valid) HTTP response headers back)
4.xx - ERR_WRITE_ERROR (Usually happens when connection is closed by origin before Akamai could send the complete request)
6.xx - ERR_CONNECT_FAIL (When Akamai is trying to connect to origin, the origin or a firewall is actively refusing the connection - e.g. it sent a TCP RST packet)
9.xx - ERR_INVALID_URL (The Akamai Edge server does not have a configuration file associated for the host/URL visited)
11.xx - ERR_DNS_FAIL (This happens if origin is specified as an FQDN and the Edgeserver cannot resolve the origin hostname to IP. e.g. due to a DNS resolver issue)
15.xx - ERR_ZERO_SIZE_OBJECT (Origin server responded with a 0 size object for a request from Akamai)
18.xx - ERR_ACCESS_DENIED (Request denied due to WAP/WAF/Botman rule or configuration (auth) setting)
24.xx - ERR_REFERER_DENIED (The referrer was denied)
27.xx - ERR_CLIENT_ABORT (The client closed the connection to Akamai edge server before the complete object could be transferred to the client - this happens when a client/user navigates away from the page during browser loading)
30.xx - ERR_FWD_SSL_HANDSHAKE (SSL certificate verification failed when connecting to the origin)
97.xx - ERR_CONNECT_TIMEOUT (Generic error where Akamai is not able to connect to origin server at a network level, TCP/IP layer)