public void setProtocol(String protocol) {
        this.protocol = protocol;
    }
<p>
The protocol used for the port mapping. Valid values are <code>tcp</code> and <code>udp</code>. The default is
<code>tcp</code>. <code>protocol</code> is immutable in a Service Connect service. Updating this field requires a
service deletion and redeployment.
</p>

@param protocol
       The protocol used for the port mapping. Valid values are <code>tcp</code> and <code>udp</code>. The
       default is <code>tcp</code>. <code>protocol</code> is immutable in a Service Connect service. Updating
       this field requires a service deletion and redeployment.
@see TransportProtocol
aws-java-sdk-ecs/src/main/java/com/amazonaws/services/ecs/model/PortMapping.java