| rfc9895v1.txt | rfc9895.txt | |||
|---|---|---|---|---|
| skipping to change at line 79 ¶ | skipping to change at line 79 ¶ | |||
| The DLEP specification does not define any flow control mechanisms. | The DLEP specification does not define any flow control mechanisms. | |||
| While in theory various flow control techniques could be implemented | While in theory various flow control techniques could be implemented | |||
| with DLEP, this document specifies a DLEP extension that introduces | with DLEP, this document specifies a DLEP extension that introduces | |||
| an Ethernet-based flow control mechanism for traffic transmitted from | an Ethernet-based flow control mechanism for traffic transmitted from | |||
| a router to a modem. This mechanism utilizes one or more logical | a router to a modem. This mechanism utilizes one or more logical | |||
| "Credit Windows", each of which is typically associated with a | "Credit Windows", each of which is typically associated with a | |||
| virtual or physical queue. The router leverages traffic flow | virtual or physical queue. The router leverages traffic flow | |||
| classification information provided by the modem to determine the | classification information provided by the modem to determine the | |||
| appropriate credit window for a given traffic flow. Credit windows | appropriate credit window for a given traffic flow. Credit windows | |||
| may be allocated on either a shared or a per-flow basis. For a | may be shared across multiple flows or used on a per-flow basis. For | |||
| Diffserv-based approach to credit window flow control, refer to | a Diffserv-based approach to credit window flow control, refer to | |||
| [RFC9894]. As specified in Section 2.3.1 of [RFC9892], when both | [RFC9894]. As specified in Section 2.3.1 of [RFC9892], when both | |||
| Diffserv and Ethernet traffic classification are applied to a flow, | Diffserv and Ethernet traffic classification are applied to a flow, | |||
| Ethernet-based classification takes precedence. | Ethernet-based classification takes precedence. | |||
| This document leverages the traffic classification and credit window | This document leverages the traffic classification and credit window | |||
| control mechanisms defined in [RFC9892] and [RFC9893] to enable | control mechanisms defined in [RFC9892] and [RFC9893] to enable | |||
| credit-window-based flow control based on DLEP destinations, Ethernet | credit-window-based flow control based on DLEP destinations, Ethernet | |||
| Virtual Local Area Networks (VLANs), and Priority Code Points (PCPs). | Virtual Local Area Networks (VLANs), and Priority Code Points (PCPs). | |||
| Ethernet PCP support is specified as part of the IEEE 802.1Q tag | Ethernet PCP support is specified as part of the IEEE 802.1Q tag | |||
| format [IEEE8021Q], which includes a 3-bit "PCP" field. The tag | format [IEEE8021Q], which includes a 3-bit "PCP" field. The tag | |||
| skipping to change at line 118 ¶ | skipping to change at line 118 ¶ | |||
| 1.1. Key Words | 1.1. Key Words | |||
| The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
| "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | |||
| "OPTIONAL" in this document are to be interpreted as described in | "OPTIONAL" in this document are to be interpreted as described in | |||
| BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all | BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all | |||
| capitals, as shown here. | capitals, as shown here. | |||
| 2. Extension Usage and Identification | 2. Extension Usage and Identification | |||
| The extension defined in this document is composed of the mechanisms | The extension defined in this document is built on the mechanisms and | |||
| and processing defined in [RFC9892] and [RFC9893]. To indicate that | processing defined in [RFC9892] and [RFC9893]. To indicate that the | |||
| the IEEE 802.1Q Aware Credit Window Extension is to be used, an | IEEE 802.1Q Aware Credit Window Extension is to be used, an | |||
| implementation MUST include the IEEE 802.1Q Aware Credit Window Type | implementation MUST include the IEEE 802.1Q Aware Credit Window | |||
| Value in the Extensions Supported Data Item (see Section 13.6 of | Extension Type Value in the Extensions Supported Data Item (see | |||
| [RFC8175]). The Extensions Supported Data Item is sent and processed | Section 13.6 of [RFC8175]). The Extensions Supported Data Item is | |||
| according to [RFC8175]. Any implementation that indicates the use of | sent and processed according to [RFC8175]. Any implementation that | |||
| the IEEE 802.1Q Aware Credit Window Extension MUST support all | indicates the use of the IEEE 802.1Q Aware Credit Window Extension | |||
| message types, Data Items, the Ethernet Traffic Classification Sub- | MUST support all message types, Data Items, the Ethernet Traffic | |||
| Data Item, and all related processing defined in [RFC9892] and | Classification Sub-Data Item, and all related processing defined in | |||
| [RFC9893]. | [RFC9892] and [RFC9893]. | |||
| The IEEE 802.1Q Aware Credit Window Extension Type Value is 5. See | The IEEE 802.1Q Aware Credit Window Extension Type Value is 5. See | |||
| Section 5. | Section 5. | |||
| 3. Management Considerations | 3. Management Considerations | |||
| This section provides several network management guidelines for | This section provides several network management guidelines for | |||
| implementations supporting the IEEE 802.1Q Aware Credit Window | implementations supporting the IEEE 802.1Q Aware Credit Window | |||
| Extension. | Extension. | |||
| skipping to change at line 151 ¶ | skipping to change at line 151 ¶ | |||
| which is configurable on both modems and routers. Diffserv Aware | which is configurable on both modems and routers. Diffserv Aware | |||
| Credit Window Extension Data Items MUST NOT be emitted by a DLEP | Credit Window Extension Data Items MUST NOT be emitted by a DLEP | |||
| participant unless such support was specified in the initialization | participant unless such support was specified in the initialization | |||
| message received from its peer. The use of the extension defined in | message received from its peer. The use of the extension defined in | |||
| this document SHOULD be configurable on both modems and routers. | this document SHOULD be configurable on both modems and routers. | |||
| Modems SHOULD support the configuration of mapping a PCP to a credit | Modems SHOULD support the configuration of mapping a PCP to a credit | |||
| window (queue). | window (queue). | |||
| Modems MAY support the configuration of mapping a PCP to a credit | Modems MAY support the configuration of mapping a PCP to a credit | |||
| window (queue) on a per-VLAN basis. VID value zero (0) is used by | window (queue) on a per-VLAN basis. VID value zero (0x0000) is used | |||
| [RFC9892] to indicate that the VID is ignored and any VID value is | by [RFC9892] to indicate that the VID is ignored and VID 0xFFFF is | |||
| used in traffic classification. | reserved. Any other VID value from 0x0001 through 0xFFFE can be used | |||
| in traffic classification. | ||||
| When VLANs are supported by a modem without support from PCPs, the | When VLANs are supported by a modem without support from PCPs, the | |||
| modem SHOULD support the configuration of mapping a VLAN to a credit | modem SHOULD support the configuration of mapping a VLAN to a credit | |||
| window (queue). | window (queue). | |||
| Modems MAY support the configuration of the number of credit windows | Modems MAY support the configuration of the number of credit windows | |||
| (queues) that they advertise to a router. | (queues) that they advertise to a router. | |||
| Routers may impose limitations on the number of queues they can | Routers may impose limitations on the number of queues they can | |||
| support and on the allowable credit window configurations. In some | support and on the allowable credit window configurations. In some | |||
| End of changes. 3 change blocks. | ||||
| 16 lines changed or deleted | 17 lines changed or added | |||
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