It's called 'cache' on the channel...
Code:
<xsd:attribute name="cache" default="auto">
<xsd:annotation>
<xsd:documentation><![CDATA[
The cache level for JMS resources: "none", "connection", "session", "consumer"
or "auto". By default ("auto"), the cache level will effectively be "consumer",
unless an external transaction manager has been specified - in which case the
effective default will be "none" (assuming J2EE-style transaction management
where the given ConnectionFactory is an XA-aware pool).
]]></xsd:documentation>
</xsd:annotation>
<xsd:simpleType>
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="none"/>
<xsd:enumeration value="connection"/>
<xsd:enumeration value="session"/>
<xsd:enumeration value="consumer"/>
<xsd:enumeration value="auto"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:attribute>