WCF Service over netTCPBinding timing out for Clients in LN, working fine for Clients in US - wcf

Question

I have a WCF Service exposed via TCPbinding running on a server in NY. I have no issues connecting to the service and getting back the results from clients connecting to this service from Americas but having issues for clients from London/Europe. I am not quite sure why this timeout issue happens but below are by Client and Server settings.
Server
<system.serviceModel>
<bindings>
<netTcpBinding>
<binding name="TCPBinding_IDataService"
receiveTimeout="00:20:00"
openTimeout="00:05:00"
maxBufferPoolSize="2147483647"
maxReceivedMessageSize="2147483647"
maxConnections="10"
maxBufferSize="2147483647">
<readerQuotas maxDepth="2147483647"
maxStringContentLength="2147483647"
maxArrayLength="2147483647"
maxBytesPerRead="2147483647"
maxNameTableCharCount="2147483647"/>
<security mode="Message">
<message clientCredentialType="Windows"/>
</security>
</binding>
</netTcpBinding>
</bindings>
<services>
<service behaviorConfiguration="DataServiceBehavior" name="DIT.Data.DRD.Service.PIERDataService">
<endpoint address="DataService" binding="netTcpBinding" bindingConfiguration="TCPBinding_IDataService"
contract="DIT.Data.DRD.Service.IPIERDataService">
<identity>
<dns value="localhost" />
</identity>
</endpoint>
<endpoint address="MEX" binding="mexTcpBinding" contract="IMetadataExchange" />
<host>
<baseAddresses>
<add baseAddress="net.tcp://localhost:9100/DRDService"/>
</baseAddresses>
</host>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="DataServiceBehavior" >
<serviceDebug includeExceptionDetailInFaults="true"/>
<serviceMetadata httpGetEnabled="false"/>
<dataContractSerializer maxItemsInObjectGraph="61200000" />
<serviceThrottling maxConcurrentCalls="100"
maxConcurrentInstances="1000"/>
</behavior>
</serviceBehaviors>
</behaviors>
<diagnostics performanceCounters="Default">
<messageLogging logEntireMessage="true" logMalformedMessages="false"
logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="false" />
</diagnostics></system.serviceModel>
My client has the following settings in C# code
private DataServiceClient GetClient(string uri, int? timeout)
{
EndpointAddress endpointAddress = new EndpointAddress(new Uri(uri),
EndpointIdentity.CreateDnsIdentity("localhost"),
new System.ServiceModel.Channels.AddressHeaderCollection());
NetTcpBinding svcBinding = new NetTcpBinding();
svcBinding.Security.Mode = SecurityMode.Message;
svcBinding.Security.Message.ClientCredentialType = MessageCredentialType.Windows;
svcBinding.MaxReceivedMessageSize = 2147483647;
svcBinding.MaxBufferPoolSize = 2147483647;
svcBinding.MaxBufferSize = 2147483647;
svcBinding.MaxConnections = 10;
svcBinding.ReaderQuotas.MaxBytesPerRead = 2147483647;
svcBinding.ReaderQuotas.MaxDepth = 2147483647;
svcBinding.ReaderQuotas.MaxArrayLength = 2147483647;
svcBinding.ReaderQuotas.MaxNameTableCharCount = 2147483647;
svcBinding.ReaderQuotas.MaxStringContentLength = 2147483647;
if (timeout.HasValue)
svcBinding.SendTimeout = svcBinding.ReceiveTimeout = new TimeSpan(0, timeout.Value, 0);
else
svcBinding.SendTimeout = svcBinding.ReceiveTimeout = new TimeSpan(0, 5, 0); // this is default
PIERDataServiceClient dsc = new PIERDataServiceClient(svcBinding, endpointAddress); //this is wcf client from ClientBase
return dsc;
}
Can someone having experience with WCF timeout issues shed some light on this? I've been trying to follow the gzillion posts on various forums but the understanding I gathered and implementation in the form of code and configuration is not helping much.
TIA,
Shravan