19.2.1.6. DMC Interworking to HiPath 3000 
Supported scenarios:
Scenario 1: HG 3500 terminates the HiPath 3000 payload switching
This scenario applies to two cases:
- the endpoint in the HiPath 4000/OpenScape 4000 network is a TDM device
or
- DMC interworking between OpenScape 4000 and HiPath 3000 is not allowed (this scenario can be achieved by setting the LCR domain end attribute in the OpenScape 4000 for the route leading to the HiPath 3000 network).
In the first case the end-to-end connection consists of a TDM connection on the OpenScape 4000 side and an IP connection between the HG 3500 and the IP endpoint on the HiPath 3000 side.In the second case the connection between the endpoint in the HiPath 4000/OpenScape 4000 network and the endpoint in the HiPath 3000 network consists of
- a DMC part in the HiPath 4000/OpenScape 4000 network and
- Payload Switching (PLS) in the HiPath 3000 network, i.e. the PLS is terminated by the HG 3500 on the OpenScape 4000 side.
This second case is shown in the following picture:
- DMC within HiPath 4000/OpenScape 4000 network: From the 1st possible A-side IP address to 1st possible B-side IP address. Signaling of A- and B-IP address takes place via CorNet-NQ (SETUP/CONNECT-messages)
- PLS (Payload Switching) within HiPath 3000 network: The IP-Gateway HG 3500 serves as Payload Switching HFA Proxy of HiPath 3000.
Scenario 2: HG 1500 terminates OpenScape 4000 Direct-Media-Connection
DMC to HG1500 in HiPath 3000
When interworking between OpenScape 4000 and HiPath 3000 is allowed
and the endpoint in the HiPath 3000 network is a TDM device the HG1500
terminates the DMC.
RTP
stream between the HiPath 3000 HG1500 and the OpenScape 4000 HG 3500
belongs to the master-connection.
Scenario 3: Direct-Media-Connection between HFA IP phones end-to-end
DMC to HFA Phone in HiPath 3000
When interworking between OpenScape 4000 and HiPath 3000 is allowed
and the endpoint in the HiPath 3000 network is a HFA phone a DMC can
be established end-to-end.
Figure 427. RTP stream between the HiPath 3000 HFA phone and HG 3500 belongs to the master-connection.
Scenario 4: OpenScape 4000 as transit node between two HiPath 3000
nodes
In
this case, no end-to-end DMC connection can be set up between the HiPath
3000 IP devices (IP phones or HG1500). On the A side, a DMC is established
to the most distant OpenScape 4000 DMC endpoint (HG 3500 (FUNCTION=HG3550
or HG3570) or HG3575). This DMC overlies a HiPath 3000 PLS connection
(not depicted in the figure) and the IP parts of the HiPath 4000/OpenScape
4000 network.
If the HiPath 4000/OpenScape 4000 network has no IP parts, the DMC
connection is omitted and the payload is transmitted on the PLS connection.
This applies if, instead of a HiPath 4000/OpenScape 4000 network or an
IPDA configuration, an individual OpenScape 4000 connected on both sides
with HiPath 3000 systems or networks is involved. So a DMC connection
on the A side only exists if an optimization is necessary.
On the B side, a payload switching connection is established.
So it always involves a connection with 2 IP hops.