Peoples, Based on the section "1.1 NSI message common attributes" of the Connection Services Architecture document I created the following common parameters structure in XML. I dropped the NSIversion since the WSDL name space will identify the version, and I also dropped the ServiceType since the WSDL service endpoint definition will cover this value. My question is with respect to the securityAttr element against each of the requesterNSA and providerNSA elements. What exactly will be contained in the securityAttr elements? Should this instead be against the entire message? I would like to understand the usefulness of these elements before committing them to the protocol specification. <!-- A common set of parameters for all NSI operations. --> <xsd:complexType name="CommonParametersType"> <xsd:sequence> <!-- NSA that requested the NSI operation (Requestor Agent). --> <xsd:element name="requesterNSA" type="tns:NsaType" /> <!-- NSA that services the NSI operation (Provider Agent). --> <xsd:element name="providerNSA" type="tns:NsaType" /> <!-- A transaction identifier provided by the requesting NSA used to correlate to an asynchronous response. --> <xsd:element name="transactionID" type="xsd:string" /> </xsd:sequence> </xsd:complexType> <xsd:complexType name="NsaType"> <xsd:sequence> <xsd:element name="nsaAddress" type="xsd:anyURI"/> <xsd:element name="securityAttr" type="tns:AttributeSequenceType"/> </xsd:sequence> </xsd:complexType> Thank you, John.