public CallIdHeader getCallId() {
// jeand : we save the header in a string form and reparse it, help GC
// for dialogs updated not too often
if (callIdHeader == null && callIdHeaderString != null) {
try {
this.callIdHeader = (CallIdHeader) new CallIDParser(
callIdHeaderString).parse();
} catch (ParseException e) {
sipStack.getStackLogger().logError(
"error reparsing the call id header", e);
}