SRX Services Gateway
SRX Services Gateway

HTTP long poll sessions on SRX

‎02-05-2014 05:16 AM

Hi Experts


We have a customer where SRX 3600 are deployed with junso 11.4R9.5 for IPTV solution.

We are having a problem for which I need your assistance.


Clients (setup boxes) connect to the portal behind firewalls on towards IP x.x.x.x port 8080.

Clients should be able to open HTTP long-poll connections towards x.x.x.x:8080.

These are basically “persistent” TCP connections, which the client start. And as long as the client is powered on, and has Internet access, these TCP connections must be kept open. That means, hours or even days 


What we see now, is that something on the flow path is killing these TCP connections from time to time.

Do we have something specific that need to be configured on SRX for this issue?




Ahmed Sharif
SRX Services Gateway

Re: HTTP long poll sessions on SRX

‎02-05-2014 07:30 AM



The default timeout for TCP on SRX is 30 minutes (1800 seconds).  So after a session is created, and there is no traffic for 30 minutes, the session is removed.


Are there any keepalives for these connections?  That would be one solution -- but lots of applications don't do keepalives.


You can create custom application with a longer timeout value.


The longest you can set is 36 hours (129600 seconds).  If you need it for longer than that, you can disable the inactivity timeout -- then the session will remain in place unless a RST or FIN is seen.



To check default timeout:




Hope this helps.




SRX Services Gateway

Re: HTTP long poll sessions on SRX

‎02-05-2014 01:17 PM

I've had a number of connections like this that require longer than the default timeouts.  We usually start with a 4 hour custom timeout and see if that is sufficient and start marching up from there:


4 hour

8 hour

16 hour

24 hour


We have not had to go beyond 24 to get the connections to be stable.

Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)