<?php
$myCurl = curl_init();

$url = "http://192.168.10.81:8080/bgbilling/executer/ru.bitel.bgbilling.kernel.contract.api/ContractService";
$data = json_encode(array(
    "method" => "contractGet",
    "user" => array(
        "user" => "admin",
        "pswd" => "xxxxxx"
    ),
    "params" => array(
        "contractId" => 1197
    )
));

echo $data."\n";

curl_setopt_array($myCurl, array(
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => $data
));
$response = curl_exec($myCurl);
curl_close($myCurl);

echo "Response: ".$response."\n";

{"method":"contractGet","user":{"user":"admin","pswd":"xxxxxx"},"params":{"contractId":1197}}
Response:

апр 18, 2016 4:24:57 PM com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit handle
SEVERE: Unsupported Content-Type: application/x-www-form-urlencoded Supported ones are: [text/xml]
com.sun.xml.ws.server.UnsupportedMediaException: Unsupported Content-Type: application/x-www-form-urlencoded Supported ones are: [text/xml]
<------>at com.sun.xml.ws.encoding.StreamSOAPCodec.decode(StreamSOAPCodec.java:299)
<------>at com.sun.xml.ws.encoding.StreamSOAPCodec.decode(StreamSOAPCodec.java:133)
<------>at com.sun.xml.ws.encoding.SOAPBindingCodec.decode(SOAPBindingCodec.java:358)
<------>at com.sun.xml.ws.transport.http.HttpAdapter.decodePacket(HttpAdapter.java:336)
<------>at com.sun.xml.ws.transport.http.HttpAdapter.access$400(HttpAdapter.java:96)
<------>at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:591)
<------>at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:259)
<------>at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:162)
<------>at ru.bitel.bgbilling.kernel.container.ws.server.JaxWSAdapter.handle(JaxWSAdapter.java:290)
<------>at bitel.billing.server.Executer.doPost(SourceFile:163)
<------>at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
<------>at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
<------>at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
<------>at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
<------>at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
<------>at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
<------>at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
<------>at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
<------>at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
<------>at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
<------>at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
<------>at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
<------>at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
<------>at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
<------>at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
<------>at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
<------>at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
<------>at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
<------>at java.lang.Thread.run(Thread.java:745)

$url = "http://192.168.10.81:8080/bgbilling/executer/json/ru.bitel.bgbilling.kernel.contract.api/ContractService";