SVC application of X.25 over FR
Network requirements
In Figure 144, Router A is connected to Router B, Router C to Router D through X.25, and Router B is connected to Router C through FR.
Configure FR Annex G DLCI 100 on the two routers to interconnect the two X.25 networks, enabling Host A and Host B to communicate with each other.
Figure 144: Network diagram
![](images/image140.png)
Configuration procedure
Configure Router A:
# Configure X.25 basic functions.
<RouterA> system-view [RouterA] interface serial 2/0 [RouterA-Serial2/0] link-protocol x25 dte [RouterA-Serial2/0] x25 x121-address 1 [RouterA-Serial2/0] x25 map ip 1.1.1.2 x121-address 2 [RouterA-Serial2/0] ip address 1.1.1.1 255.0.0.0
Configure Router D:
# Configure X.25 basic functions.
<RouterD> system-view [RouterD] interface serial 2/0 [RouterD-Serial2/0] link-protocol x25 dte [RouterD-Serial2/0] x25 x121-address 2 [RouterD-Serial2/0] x25 map ip 1.1.1.1 x121-address 1 [RouterD-Serial2/0] ip address 1.1.1.2 255.0.0.0
Configure Router B:
# Enable X.25 switching.
<RouterB> system-view [RouterB] x25 switching
# Configure Serial 2/0 as an X.25 interface.
[RouterB] interface serial 2/0 [RouterB-Serial2/0] link-protocol x25 dce
# Configure Serial 2/1 as an FR interface.
[RouterB] interface serial 2/1 [RouterB-Serial2/1] link-protocol fr [RouterB-Serial2/1] fr interface-type dce
# Configure the FR Annex G DLCI.
[RouterB-Serial2/1] fr dlci 100 [RouterB-fr-dlci-Serial2/1-100] annexg dce
# Configure X.25 local switching.
[RouterB] x25 switch svc 1 interface serial 2/0
# Configure X.25 over FR switching.
[RouterB] x25 switch svc 2 interface serial 2/1 dlci 100
Configure Router C:
# Enable X.25 switching.
<RouterC> system-view [RouterC] x25 switching
# Configure Serial 2/0 as X.25 interface.
[RouterC] interface serial 2/0 [RouterC-Serial2/0] link-protocol x25 dce
# Configure Serial 2/1 as FR interface.
[RouterC] interface serial 2/1 [RouterC-Serial2/1] link-protocol fr
# Configure the FR Annex G DLCI.
[RouterC-Serial2/1] fr dlci 100 [RouterC-fr-dlci-Serial2/1-100] annexg dte
# Configure X.25 local switching.
[RouterC] x25 switch svc 2 interface serial 2/0
# Configure X.25 over FR switching.
[RouterC] x25 switch svc 1 interface serial 2/1 dlci 100