code: public void setCharacterEncoding(String enc) throws UnsupportedEncodingException {
  		new String("testEncoding".getBytes(),enc);
  		checkCommitted();
  		try {
  			this.message.setContentEncoding(SipFactoryImpl.headerFactory
  					.createContentEncodingHeader(enc));
  		} catch (Exception ex) {
  			throw new UnsupportedEncodingException(enc);
  		}
  
  	}
docs: /*
  (non-Javadoc)
  @see javax.servlet.sip.SipServletMessage#setCharacterEncoding(java.lang.String)