17
Figure 9 Dynamically establishing an LSP
Label distribution and control
Label advertisement modes
Figure 10 Label advertisement modes
LDP advertises label-FEC mappings in one of the following ways:
•
Downstream Unsolicited (DU) mode
—Distributes FEC-label mappings to the upstream LSR,
without waiting for label requests. The device supports only the DU mode.
•
Downstream on Demand (DoD) mode
—Sends a label request for an FEC to the downstream
LSR. After receiving the label request, the downstream LSR distributes the FEC-label mapping
for that FEC to the upstream LSR.
NOTE:
A pair of upstream and downstream LSRs must use the same label advertisement mode. Otherwise,
the LSP cannot be established.
LSR A
LSR B
LSR D
LSR C
LSR E
LSR F
LSR G
LSR H
Ingress
Egress
LSP
Label mapping
Egress
Transit
DU mode
DoD mode
2) Sends a label request for the
FEC to the downstream.
3) Distributes a label mapping for
the FEC to the upstream upon
receiving the request.
Ingress
1) Unsolicitedly distributes a label
mapping for a FEC to the
upstream.
2) Unsolicitedly distributes a label
mapping for the FEC to the
upstream.
1) Sends a label request for a
FEC to the downstream.
4) Distributes a label mapping for
the FEC to the upstream upon
receiving the request.
Содержание FlexNetwork 5510 HI Series
Страница 9: ...vii Remote support 460 Documentation feedback 460 Index 462 ...
Страница 318: ...309 Request list 0 Retransmit list 0 ...
Страница 363: ...354 Verify that CE 1 and CE 2 can ping each other Details not shown ...
Страница 446: ...437 The MCE has redistributed the OSPF routes of the two VPN instances into the EBGP routing tables of PE 1 ...