[1.2.3] How to modify configurations for embedded netty (3.2.4) server?

[The Thinker]

Is it possible to set / modify configurations for embedded netty
(3.2.4) server with Play Framework (1.2.3)?

I am facing scalability issues while performing stress testing on my
application with JMeter.
Result shows that Play Server / Netty is not able to serve more than
120 simultaneous requests (with 0 ramp up time) and gives following
response in JMeter:

Response code: Non HTTP response code: java.net.ConnectException
Response message: Non HTTP response message: Connection timed out:
connect

java.net.ConnectException: Connection timed out: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.<init>(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at
sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown
Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown
Source)
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown
Source)
at
org.apache.jmeter.protocol.http.sampler.HTTPJavaImpl.sample(HTTPJavaImpl.java:
479)
at
org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy.sample(HTTPSamplerProxy.java:
62)
at
org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:
1054)
at
org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:
1043)
at
org.apache.jmeter.threads.JMeterThread.process_sampler(JMeterThread.java:
416)
at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:271)
at java.lang.Thread.run(Unknown Source)

Tranversing through few online content, I found that I need to set few
netty server properties like connectTimeoutMillis, keepAlive.
Is it possible to do that in above mentioned environment setup? If
yes, how? If not, what specific things should be done here or Am I
missing anything?

Any help would highly be appreciated.
Thanks.