100 Continue

From: Clinton Wong <clintdw@netcom.com> Date: Tue, 8 Oct 1996 16:15:40 -0700 (PDT) Message-Id: <199610082315.QAA28288@netcom12.netcom.com> To: www-talk@w3.org · This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 27 October 2010 18:14:19 GMT

Questions about HTTP 1.1's new status code of 100 (Continue).

1.  How does this status code make HTTP more efficient?  The
    spec states that the client will know that its request (so far)
    hasn't been rejected and it is okay to continue the request.
    I'm not sure how this status code is more efficient than 
    the client finishing up its request and receiving an error
    code.  Can someone think of an example that explains this
    more?  I'm thinking that 1 or 2 packets are saved by doing this.
    Or are there greater savings?  (Does anyone have research
    findings they would like to share?)

2.  It appears that multiple response codes are possible...
    I'm not sure if I am interpreting this correctly... is it like this?

Client:

GET / HTTP/1.1
[headers go here]
CRLF
entity-body

Server:
HTTP/1.1 100 Continue    [midway between the client's request]
HTTP/1.1 200 OK          [when the client is finished requesting]
[headers go here]
CRLF
entity-body

Is this the correct interpretation?  

Regards,
Clinton Wong