Why are phone numbers signaled without a leading zero on a HiPath 3000?

When using the HiPath 3000 V8 and IP trunking (XCAPI connection), it can happen that the leading zero is missing in the call number signaling.

To prevent this, the "E.164" flag must be set under System parameters/Flags in HiPath Manager E.

The missing E.164 flag can also have the consequence that the displayed call number is no longer displayed for calls that are connected further.