RE: Questions on HTTP URI schemes and QUIC

[Sridhar Bhaskaran <[e-mail]>]

Thank you Lucas and Patrick for the clarification. The hint-helium presentation was very useful. It was just pure co-incidence of me asking this question. I did not attend the session in IETF 102.

For the background, 3GPP CT4 is doing a study on the use of QUIC as transport protocol for the 5G control plane interfaces. The 5G control plane interfaces use HTTP APIs (HTTP/2 over TCP) in 3GPP Release 15. The objective of this new study is to look into the benefits of replacing TCP with QUIC from Release 16 onwards.

I am the rapporteur for that study. The study objectives can be found at 

http://www.3gpp.org/ftp/tsg_ct/TSG_CT/TSGC_80_La_Jolla/Docs/CP-181194.zip

In 5G control plane architecture there is a network function called "Security Protection and Edge Proxy - SEPP" which sits at the edge of each PLMN (an operator's network) connecting the network functions of one PLMN with the other PLMN. I was wondering how http:// and https:// scheme APIs would work when SEPP, as a proxy, supports QUIC and the network functions in the two PLMNs support QUIC and they communicate via SEPP which is a HTTP/QUIC proxy. Looks like this latter scenario is bit challenging as there is no standard means as highlighted in slide 6.

Note that this SEPP is not a blind forwarding proxy. It does message transformations based on operator policies. So as highlighted in slide 8 SEPP's role is "in the loop". 

Thanks
Sridhar

-----Original Message-----
From: Lucas Pardue [mailto:[e-mail]] 
Sent: Wednesday, July 18, 2018 7:22 PM
To: Sridhar Bhaskaran <[e-mail]>; IETF QUIC WG <[e-mail]>
Subject: RE: Questions on HTTP URI schemes and QUIC

Hi Sridhar,

I presented some slides [1] about HTTP proxying (including HTTP over QUIC) at the IETF 102 HTTPbis session this week. I'm not sure if your questions are motivated by that session, or if it is coincidence. There are some visualisations of the various tunnelling options (as I understand them) across the main slides and backup slides.

Regards
Lucas

[1] - https://github.com/httpwg/wg-materials/blob/gh-pages/ietf102/hint-helium.pdf

>-----Original Message-----
>From: QUIC [mailto:[e-mail]] On Behalf Of Sridhar 
>Bhaskaran
>Sent: 18 July 2018 11:50
>To: IETF QUIC WG <[e-mail]>
>Subject: Questions on HTTP URI schemes and QUIC
>
>Dear Quic experts,
>
>I am Sridhar Bhaskaran from Huawei. Going through the drafts on QUIC 
>transport and HTTP over QUIC, I have the following queries
>
>1. If a HTTP URI uses http:// scheme and the origin server advertises 
>alternate service via QUIC, can a HTTP client use QUIC to connect to 
>the origin server and still use the http:// scheme URI?
>2. If a HTTP URI uses https:// scheme and the HTTP client is configured 
>to connect to a HTTP proxy and if the HTTP proxy supports QUIC, my 
>understanding is the following sequence of events
>	a. HTTP client to HTTP proxy QUIC connection is setup
>	b. HTTP client issues a HTTP CONNECT request to the proxy with the 
>":authority" HTTP/2 pseudo header pointing to the origin server
>	c. HTTP proxy upon getting the CONNECT request sets up a TCP 
>connection with the origin server
>	d. HTTP proxy sends HTTP CONNECT response to the client
>	e. HTTP client then initiates a TLS connection towards the origin 
>server via the proxy and the proxy simply tunnels it.
>	f. Actual HTTP traffic happens between client and origin server
>
>Is this correct?
>
>Where I am not clear is whether step /e/ actually happens. If it does, 
>then for step /f/ is the client required to do ciphering 2 times - one 
>for the TLS and other for the QUIC connection to proxy itself.
>
>Could you please clarify?
>
>Thanks
>Sridhar