Configuring a Dynamic DS-TE Tunnel
Pre-configuration Tasks
DS-TE provides QoS guarantee based on service types. Dynamic DS-TE tunnels are established using the RSVP-TE signaling protocol that can adjust the path of a DS-TE tunnel according to network changes. There is no need to manually configure each hop on a large scale network. Before configuring all advanced MPLS TE features and applications, configure a dynamic DS-TE tunnel.
Before configuring a dynamic DS-TE tunnel, complete the following tasks:
Configure an IGP to ensure reachable routes between nodes.
Configure an LSR ID for each node.
Enable MPLS globally on each node.
Enable MPLS on each interface of each node.
- Enabling MPLS TE and RSVP-TE
- Configuring an MPLS TE Tunnel Interface
- Configuring DS-TE Mode
- Configuring DS-TE Bandwidth Constraints Model
- (Optional) Configuring TE-Class Mapping Table
- Configuring Link Bandwidth
- Advertising TE Link Information
- Configuring Constraints for the DS-TE Tunnel
- Configuring Path Calculation
- Configuring the Packet Priority Trusted by the Inbound Interface
- (Optional) Configuring Mappings Between CTs and Services and
the Scheduling Mode
- Verifying the Static DS-TE Tunnel Configuration
Enabling MPLS TE and RSVP-TE
Context
To create a dynamic MPLS TE tunnel, first enable MPLS TE, enable RSVP-TE globally, enable RSVP-TE on an interface, and perform other configurations, such as setting the link bandwidth attributes and enabling CSPF.
Perform the following configurations on each node of the MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls te
MPLS TE is enabled on the node globally.
- Run mpls rsvp-te
RSVP-TE is enabled on the node.
- Run quit
The system view is displayed.
- Run interface interface-type interface-number
The MPLS TE interface view is displayed.
- Run mpls
The MPLS is enabled on the interface.
- Run mpls te
The MPLS TE is enabled on the interface.
- Run mpls rsvp-te
RSVP-TE is enabled on the interface.
Configuring an MPLS TE Tunnel Interface
Context
A tunnel interface must be created on the ingress so that a tunnel can be established and forward data packets.
- Establishes a tunnel. Tunnel constraints, bandwidth attributes, and advanced attributes such as TE FRR and tunnel re-optimization can be configured on the tunnel interface to establish the tunnel.
- Manages a tunnel. Tunnel attributes can be modified on the tunnel interface to manage the tunnel.
NOTE: Because MPLS TE tunnels forward MPLS packets, not IP packets, IP forwarding-related commands run on the tunnel interface are invalid.
Perform the following configurations on the ingress node of an MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run interface tunnel interface-number
A tunnel interface is created and the tunnel interface view is displayed.
If the shutdown command is run on the tunnel interface, all tunnels established on the tunnel interface will be deleted.
- Run either of the following commands to assign an IP address to the tunnel interface:
To configure an IP address for the tunnel interface, run:ip address ip-address { mask | mask-length } [ sub ]
The primary IP address must be configured before the secondary IP address is configured.
To configure the tunnel interface to borrow an IP address of another interface, run:ip address unnumbered interface interface-type interface-number
An MPLS TE tunnel can be established even if the tunnel interface is assigned no IP address. The tunnel interface must obtain an IP address before forwarding traffic. The MPLS TE tunnel is unidirectional and does not need to configure a separate IP address for the tunnel interface. Generally, a loopback interface is created on the ingress node and a 32-bit address that is the same as the LSR ID is assigned to the loopback interface. Then the tunnel interface borrows the IP address of the loopback interface.
- Run tunnel-protocol mpls te
MPLS TE is configured as a tunnel protocol.
- Run destination dest-ip-address
A tunnel destination address is configured, which is usually the LSR ID of the egress.
Various types of tunnels require specific destination addresses. If a tunnel protocol is changed from another protocol to MPLS TE, a configured destination address is deleted automatically and a new destination address needs to be configured.
- Run mpls te tunnel-id tunnel-id
A tunnel ID is set.
- Run mpls te signal-protocol rsvp-te
RSVP-TE is configured as the signaling protocol.
- (Optional) Run mpls te signalled tunnel-name tunnel-name
The tunnel name is specified.
By default, the tunnel interface name such as Tunnel0/0/1 is used as the name of the TE tunnel.
Perform this step to fulfill the following purposes:- Facilitate TE tunnel management.
- Allow a Huawei device to be connected to a non-Huawei device that uses a tunnel name that differs from the tunnel interface name.
- (Optional) Run mpls te cspf disable
Do not perform the constraint shortest path first (CSPF) calculation when an MPLS TE tunnel is being set up.
- Run mpls te commit
The configuration is committed.
NOTE:
The mpls te commit command must be run to make configurations take effect each time MPLS TE parameters are changed on a tunnel interface.
Configuring DS-TE Mode
Context
You can configure the non-IETF mode or the IETF mode for a DS-TE tunnel.
The non-IETF (non-standard) mode supports two CTs (CT0 and CT1), eight priorities (0-7), and two bandwidth constraint models (Russian Dolls Model [RDM] and Maximum Allocation Model [MAM]).
The CT refers to the class type of a specific service flow. The priority refers to the LSP preemption priority.
- The IETF (standard) mode supports eight CTs (CT0 to CT7), eight priorities (0-7), and three bandwidth constraint models (RDM, MAM, and extended MAM).
Perform the following configurations on each node of the MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls te ds-te mode { ietf | non-ietf }
The DS-TE mode is configured.
By default, the non-IETF mode is used.
Follow-up Procedure
On the device, the non-IETF mode and the IETF mode can be switched to each other.
NOTE: When the non-IETF DS-TE mode is switched to the IETF DS-TE mode, the user configurations cannot be lost or modified. However, when the IETF DS-TE mode is switched to the non-IETF DS-TE mode, the user configurations that are supported in the non-IETF mode but are not supported in the non-IETF mode are lost or modified as follows:
- The extended-MAM configured in IETF DS-TE mode is automatically switched to the MAM, which may result in a tunnel re-establishment failure.
- The interface bandwidth values set for BC2 to BC7 in IETF DS-TE mode are deleted.
Item |
Non-IETF → IETF |
IETF → Non-IETF |
|---|---|---|
Change in the bandwidth constraints model |
The bandwidth constraints model is unchanged. |
The bandwidth constraints model is changed as follows: The extended-MAM is changed to the MAM. The RDM is unchanged. The MAM is unchanged. |
Change in the bandwidth |
The bandwidth values of BC0 and BC1 are unchanged. |
Other BC values are reset to zero except values of BC0 and BC1. |
TE-class mapping table |
If the TE-class mapping table is configured, it is applied. Otherwise, the default one is applied.
NOTE:
For information about the default TE-class mapping table, see Table 4-35. |
The TE-Class mapping table is not applied.
|
LSP deletion |
LSPs whose combination of <CT, set-priority> or <CT, hold-priority> is not in the TE-class mapping table are deleted. |
The following LSPs are deleted:
|
Configuring DS-TE Bandwidth Constraints Model
Context
If preemption for CT bandwidth is enabled, you are recommended to use the RDM, which effectively uses bandwidth. If preemption for CT bandwidth is disabled on a network, you are recommended to use the MAM or the extended-MAM.
Perform the following configurations on each node of the MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls te ds-te bcm { extend-mam | mam | rdm }
The DS-TE bandwidth constraints model is configured.
By default, the DS-TE bandwidth constraints model is the RDM.
The DS-TE non-IETF mode does not support the extended-MAM.
(Optional) Configuring TE-Class Mapping Table
Context
This configuration procedure is unnecessary to the non-IETF DS-TE.
For IETF DS-TE, it is recommended that the TE-class mapping tables applied to the entire DS-TE domain are the same. Otherwise, Some LSPs may not be set up correctly.
When configuring a TE-class mapping table, pay attention to the following information:
- Each DS-TE node has one TE-class mapping table at most.
- TE-class is a global concept, that is, TE-class is applied to all DS-TE tunnels of the LSR.
- A TE-class indicates the combination of a Class-Type (CT) and priority. The priority indicates the priority for CR-LSP preemption rather than the value of the EXP field in the MPLS packet header. The value of the preemption priority ranges from 0 to 7. The smaller the value is, the higher the priority is. A CR-LSP can be set up only when both the combination of its CT and setup priority (<CT, setup-priority>) and the combination of its CT and holding priority
(<CT, hold-priority>) exist in the TE-class mapping table. For example, suppose the TE-class mapping table of a certain node contains only TE-Class[0] = <CT0, 6> and TE-Class[1] = <CT0, 7>. Only the following types of CR-LSPs can be set up successfully:
- Class-Type = CT0, setup-priority = 6, hold-priority = 6
- Class-Type = CT0, setup-priority = 7, hold-priority = 6
- Class-Type = CT0, setup-priority = 7, hold-priority = 7
NOTE:
The setup-priority cannot be higher than the hold-priority. Therefore, the LSP, whose Class-Type is CT0, setup-priority is 6, holding priority is 7, does not exist.
- In the MAM and extended-MAM, the CT of a higher priority can preempt the bandwidth of CTs of the same type. CTs of different types do not preempt the bandwidth of each other.
- In the RDM, the preemption of bandwidth among CTs is determined by the preemption priority and the corresponding bandwidth constraint. Assume m and n are preemption priorities (0<=m<n<=7) and i and j are CT values (0<=i<j<=7).
- CTi with priority m can preempt the bandwidth of CTi with priority n or the bandwidth of CTj with priority n.
- The total bandwidth of CTi is equal to or less than the bandwidth of BCi.
- When the bandwidth of all CTs along an LSP meets the requirements, the preemption can be performed and the LSP can be set up.
Perform the following configurations on each node of the DS-TE tunnel in DS-TE IETF mode.
Procedure
- Run system-view
The system view is displayed.
- Run te-class-mapping
A TE-class mapping table is configured and the TE-Class mapping table view is displayed.
- Run one or multiple commands as follows to configured TE-Classes:
- To configure TE-Class0, run:
te-class0 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
- To configure TE-Class1, run:
te-class1 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
- To configure TE-Class2, run:
te-class2 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
- To configure TE-Class3, run:
te-class3 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
- To configure TE-Class4, run:
te-class4 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
- To configure TE-Class5, run:
te-class5 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
- To configure TE-Class6, run:
te-class6 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
- To configure TE-Class7, run:
te-class7 class-type { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority [ description description-info ]
In DS-TE IETF mode, when the TE-class mapping table is not configured, the default TE-class mapping table is applied. See Table 4-35.
NOTE:
After a TE-class is configured, you can run the { te-class0 | te-class1 | te-class2 | te-class3 | te-class4 | te-class5 | te-class6 | te-class7 } description description-info command to modify the TE-class description.
- To configure TE-Class0, run:
Configuring Link Bandwidth
Context
By configuring the link bandwidth, you can limit the bandwidth of a DS-TE tunnel.
In different bandwidth constraints models, the relationships between the reservable bandwidth and the bandwidth of each BC are different.
- In the RDM: max-reservable-bandwidth ≥ bc0-bw-value ≥ bc1-bw-value ≥ bc2-bw-value ≥ bc3-bw-value ≥ bc4-bw-value ≥ bc5-bw-value ≥ bc6-bw-value ≥ bc7-bw-value
- In the MAM: max-reservable-bandwidth ≥ bc0-bw-value + bc1-bw-value + bc2-bw-value + bc3-bw-value + bc4-bw-value + bc5-bw-value + bc6-bw-value + bc7-bw-value
- In the Extended-MAM: It is the same as the MAM.
BC is the bandwidth constraint for outgoing interface, while CT bandwidth is the bandwidth of the class type of DS-TE tunnel. The total bandwidth of BCi (0 ≤ i ≤ 7) of an interface is equal to or greater than the CTi bandwidth of all tunnels passing through this outgoing interface. For example, three LSPs of CT1 pass through a link and their bandwidth values are x, y, and z respectively. The bandwidth of BC1 of the link should be equal to or greater than the total bandwidth of x, y, and z.
NOTE: - MAM/Extended-MAM: BCi bandwidth ≥ CTi bandwidth x 125% (0 ≤ i ≤ 7)
- RDM: BCi bandwidth ≥ sum of CTi to CT7 bandwidths x 125% (0 ≤ i ≤ 7)
Perform the following steps on the outbound interface of each node of the DS-TE tunnel:
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The view of the outbound interface of the link is displayed.
- Run mpls te bandwidth max-reservable-bandwidth bw-value
The maximum reservable bandwidth of the link is configured.
- Configure the link bandwidth.
- In non-IETF mode, run the mpls te bandwidth { bc0 bc0-bw-value | bc1 bc1-bw-value } * command.
- In IETF mode, run the mpls te bandwidth { bc0 bc0-bw-value | bc1 bc1-bw-value | bc2 bc2-bw-value | bc3 bc3-bw-value | bc4 bc4-bw-value | bc5 bc5-bw-value | bc6 bc6-bw-value | bc7 bc7-bw-value } * command.
Advertising TE Link Information
Context
OSPF TE
OSPF TE is an OSPF extension used on an MPLS TE network. LSRs on the MPLS area exchange Opaque Type 10 LSAs that carry TE link information to generate TEDBs for CSPF calculation.
OSPF areas do not support TE by default. The OSPF Opaque capability must be enabled to support OSPF TE, and a node can generate Opaque Type 10 LSAs only if at least one OSPF neighbor is in the Full state.
NOTE:
If OSPF TE is disabled, no Opaque Type 10 LSA is generated or exchanged by nodes to generate TEDBs. On an OSPF TE-incapable network, CR-LSPs are established using OSPF routes but not CSPF calculation results.
IS-IS TE
IS-IS TE is an IS-IS extension used on an MPLS TE network. IS-IS TE defines a new TLV in Link State Packets (LSPs) and IS-IS TE-enabled nodes send these LSPs to flood and synchronize TE link information. IS-IS TE extracts TE link information from LSPs and then transmits the TE link information to the CSPF module for calculating tunnel paths.
Use the mode in which TE information is advertised according to the IGP used on the backbone network. Perform the following operations on each node of an MPLS TE tunnel.
Configuring Constraints for the DS-TE Tunnel
Context
By configuring explicit path and tunnel bandwidth on the ingress node, you can flexibly control the establishment of a DS-TE tunnel. When specifying the bandwidth, ensure that the bandwidth of LSPs of all CTs is not greater than the bandwidth of all BCs.
Perform the following configurations on the ingress node of a DS-TE tunnel.
Procedure
- Configure an MPLS TE explicit path.
- Configure constraints for the DS-TE tunnel.
- Run one of the following commands to configure the bandwidth
of the MPLS TE tunnel interface.
Configure a single CT.
In non-IETF mode, run the mpls te bandwidth { ct0 ct0-bw-value | ct1 ct1-bw-value } command.
In IETF mode, run the mpls te bandwidth { ct0 bw-value | ct1 bw-value | ct2 bw-value | ct3 bw-value | ct4 bw-value | ct5 bw-value | ct6 bw-value | ct7 bw-value } command.
Configure multiple CTs.
In IETF mode, run the mpls te bandwidth { ct0 bw-value | ct1 bw-value | ct2 bw-value | ct3 bw-value | ct4 bw-value | ct5 bw-value | ct6 bw-value | ct7 bw-value } * command.
NOTE:
In tunnel policy, the multiple class type (multi-CT) CR-LSP supports only the VPN tunnel binding mode rather than the select-sequence mode.
On one node in any the Bandwidth Constraints model, the total bandwidth of CTi is not more than the bandwidth of BCi (0 <= i <= 7) irrespective of. That is, CTi can use only the bandwidth of BCi.
For instance, the bandwidth of BC1 on a PE is x and two CR-LSPs are set up on the node with their CT1 bandwidth being y and z respectively. The total bandwidth of CT1 (y + z) is not more than the bandwidth of BC1 (x).
- Run one of the following commands to configure the bandwidth
of the MPLS TE tunnel interface.
Configuring Path Calculation
Context
To calculate a tunnel path meeting specified constraints, CSPF should be configured on the ingress.
- Link state information sent by IGP-TE and saved in TEDBs
- Network resource attributes, such as the maximum available bandwidth, maximum reservable bandwidth, and affinity property, sent by IGP-TE and saved in TEDBs
- Configured constraints such as explicit paths
NOTE: An RSVP-TE tunnel can be established on a CSPF-disabled ingress. However, to allow a path to meet tunnel constraints, you are advised to enable CSPF on the ingress before establishing the RSVP-TE tunnel.
Enabling CSPF on all transit nodes is recommended. The tunnel function fails if CSPF or IGP TE is not enabled on the ingress, IGP TE is not enabled on some transit nodes or the egress, and CSPF is enabled on some transit nodes.
Perform the following configurations on the ingress node of an MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls te cspf
CSPF is enabled on a node.
CSPF is disabled by default.
- (Optional) Run mpls te cspf preferred-igp { isis [ isis-process-id [ level-1 | level-2 ] ] | ospf [ ospf-process-id [ area { area-id-1 | area-id-2 } ] ] }
A preferred IGP is specified.
By default, OSPF is preferred for CSPF path calculation.
If a single IGP protocol is only configured on the backbone network to advertise OSPF or IS-IS TE information, ignore this step.
Configuring the Packet Priority Trusted by the Inbound Interface
Context
After a DS-TE tunnel is configured, you need to configure the packet priority trusted by the inbound interface to provide differentiated services.
Procedure
- Configure the ingress.
Perform the following configurations on the inbound interface of the ingress node of the DS-TE tunnel.
- Configure the transit.
Perform the following configurations on the inbound interface of the transit node of the DS-TE tunnel.
- Configure the egress.
Perform the following configurations on the inbound interface of the egress node of the DS-TE tunnel.
(Optional) Configuring Mappings Between CTs and Services and the Scheduling Mode
Context
After a DS-TE tunnel is established, you can configure mappings between CTs and services and the scheduling mode.
Procedure
- Configure mapping between CTs and services.
Perform the following configurations on each node of a DS-TE tunnel. You are advised to carry out overall planning in advance and configure the same mappings on all the nodes.
- Configure the scheduling mode.
Perform the following configurations on the outbound interfaces on each node of the DS-TE tunnel.
Verifying the Static DS-TE Tunnel Configuration
Procedure
- Run the display mpls te ds-te { summary | te-class-mapping [ default | config | verbose ] } command to check information about DS-TE.
- Run the display mpls te te-class-tunnel { all | { ct0 | ct1 | ct2 | ct3 | ct4 | ct5 | ct6 | ct7 } priority priority } command to check TE tunnels associated with the TE-classes.
- Run the display interface tunnel interface-number command to check information about traffic of each CT on the tunnel interface.