This article describes how to configure SPDY on a NetScaler appliance.

Background

SPDY is an open networking experimental protocol developed by Google to reduce the time that a client takes to load a web page in a browser. An application layer protocol, SPDY changes the way in which HTTP requests and responses are handled. SPDY offers the following advantages compared to a regular HTTP transaction:

• Multiplexed requests and responses: In a single SPDY session, multiple requests from the client can be sent over a single TCP connection to the server. This reduces the number of TCP connections and also optimizes usage of each TCP connection.

• Request prioritization: When requesting services from the server, a client can assign a priority to each request.

• Header Compression: SPDY compresses the HTTP request and response headers, saving bandwidth and reducing latency.

• Server push: The server can send data to the client before the client requests it.

• Security: SPDY is secure by design because SSL is required for SPDY connections.

​Requirements

• NetScaler software release 10.1 or later.

• SPDY enabled browser.

• If you use a NetScaler appliance as a SPDY gateway for the servers, the servers do not have to support SPDY.

• Both ends of a SPDY connection must support the same version of SPDY. Additionally, the clients must meet the following requirements:

  • Support ZLIB compression and accept compressed data.
  • Support the Next Protocol Negotiation (NPN) Transport Layer Security (TLS) extension, because NPN is used in the TLS handshake.

Instructions

Note: If you are using NetScaler version 10.5, 11 or 11.1 then refer to Citrix Documentation - SPDY (Speedy) to configure SPDY on NetScaler appliance.

To configure SPDY on NetScaler 10.1, complete the following procedure:

NetScaler GUI

1. Select System > Profiles from the Configuration utility of the NetScaler appliance.

2. In the Details pane, select HTTP Profile.

3. Click Add.

4. Enable SPDY.

5. Click Create.

   

6. Select Traffic Management > Load Balancing > Virtual Servers.

7. Open the SSL virtual server.

8. Select Profiles.

9. Select spdy_enabled for HTTP Profile.

10. Click OK.

    

NetScaler CLI

Alternatively, run the following commands from the command line interface to configure SPDY on a NetScaler appliance:

add ns httpProfile spdy_enabled -dropInvalReqs DISABLED -markHttp09Inval DISABLED -markConnReqInval DISABLED -cmpOnPush DISABLED -conMultiplex ENABLED -maxReusePool 0 -dropExtraCRLF ENABLED -incompHdrDelay 7000 -webSocket DISABLED -reqTimeout 0 -adptTimeout DISABLED -reqTimeoutAction DROP -dropExtraData DISABLED -webLog ENABLED -maxReq 0 -persistentETag DISABLED -spdy ENABLED
set lb vserver lbvservername -httpProfileName spdy_enabled 

Verifying SPDY

To verify SPDY, complete any of the following tasks:

• Run the following command from the command line interface of the appliance to verify the HTTP statistics and the SPDY rate/s and total requests:
  > stat protocol http -detail

  HTTP Statistics
  Requests:
                                            Rate (/s)                Total
  Total requests                                     1                29159
  GETs                                               0                28535
  POSTs                                              0                   23
  Other methods                                      0                  601
  HTTP/1.0 requests                                  0                    0
  HTTP/1.1 requests                                  0                28560
  Content-length requests                            0                   23
  Chunked requests                                   0                    0
  Request bytes received                            69              5115347
  Request bytes transmitted                          0                    0
  Responses:
                                            Rate (/s)                Total
  Total responses                                    1                29103
  ---SNIP------
  SPDY:
                                            Rate (/s)                Total
  SPDYv2 requests                                    0                   55

• You can also verify the SPDY Header in Firefox Live HTTP Headers.

  

• After capturing a NetScaler packet trace, you must see server response packets with the Next Protocol Negotiation Extension. Use the following Wireshark filter: ssl.handshake.extensions_npn, as shown in the following screen shot:

  

Note: NetScaler does not support NPN over TLS 1.1/1.2. To use SPDY, the client must disable TLS1.1/1.2 in the browser:

• Chromium Projects - SPDY