No, the CANCEL method is hop-by-hop request used to terminate pending calls or searches. A proxy receiving a CANCEL immediately SENDS a 200 OK response BACK to the sender and GENERATES a new CANCEL, which is then FORWARDED to the next hop. Similar behaviour can be found in 3xx, 4xx, 5xx, and 6xx responses to an INVITE request. While an ACK to a 2xx response is generated by the end point, a 3xx, 4xx, 5xx, or 6xx response is acknowledged on a hop-by-hop basis. A proxy SERVER receiving one of these responses immediately generates an ACK back to the sender and forwards the response to the next hop.

No, the CANCEL method is hop-by-hop request used to terminate pending calls or searches. A proxy receiving a CANCEL immediately sends a 200 OK response back to the sender and generates a new CANCEL, which is then forwarded to the next hop. Similar behaviour can be found in 3xx, 4xx, 5xx, and 6xx responses to an INVITE request. While an ACK to a 2xx response is generated by the end point, a 3xx, 4xx, 5xx, or 6xx response is acknowledged on a hop-by-hop basis. A proxy server receiving one of these responses immediately generates an ACK back to the sender and forwards the response to the next hop.