EAI HTTP Transport does not read the sleep time parameter from the enterprise or object manager settings. Instead, it defaults to 120 seconds internally (hardcoded). The default can be changed if you explicitly pass the value as input to the business se

 Siebel Application does not support REST web services on Siebel 8.0.x version, inbound .REST inbound web service support is GA in release 8.1.1.4.For more information on REST support please refer to this MOS posting:
- Siebel REST Service - Quick Start Guide [ID 988872.1] - ACR 599: Siebel REST Service Implementation Guide [ID 980769.1] I understand REST services are based on pure HTTP calls though.Specifically for the OUTBOUND scenario, nothing new is added by release 8.1.1.4.Outbound scenarios are similar to "pure" HTTP calls and EAI HTTP Transport business service is already capable of doing that on any siebel release.Siebel does have the EAI HTTP Transport, XML converters , eScript programming language and workflows, all of which can be leveraged to build a custom solution to call OUTBOUND REST services.
Customization is needed to build the message to be sent out and to read the message received.
EAI HTTP Transpor can make an http call to send data and receive responses back.
This works in all Siebel versions.
The customization effort is unknown though and we recommend you consider a billable consulting engagement to assist you further.