ISIS-TE
Extensions for Enhanced DetNetHuaweigengxuesong@huawei.comHuaweilizhenbin@huawei.comHuaweizhoutianran@huawei.com
Routing Area
LSR Working GroupSampleDraftThis document defines extensions to ISIS to distribute the enhanced
DetNet information at node and/or link granularity.The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119.DetNet() provides the capability to carry
specified unicast or multicast data flows with extremely low data loss
rates and bounded end-to-end latency within a network domain. Three
primary goals of DetNet QoS are defined in section 3.1 of :Minimum and maximum end-to-end latency from source to
destination, timely delivery, and bounded jitter (packet delay
variation) derived from these constraints.Packet loss ratio under various assumptions as to the operational
states of the nodes and links.An upper bound on out-of-order packet delivery. It is worth
noting that some DetNet applications are unable to tolerate any
out-of-order delivery.This document defines extensions to ISIS to distribute the
inforamtion for bounded latency(enhanced DetNet) at node and/or link
granularity.Some of information (e.g., Link delay/loss ) can be distributed and
collected through Traffic Engineering (TE) metric
extensions and , which will not be
redefined by this document.All the DetNet related terminologies used in this document conform to
the DetNet
architecture.This document defines an extension to IS-IS used to advertise DetNet
information.The DetNet Processing Delay Sub-TLV is defined within the body of
the IS-IS Router Capability TLV [RFC7981] to carry Enhanced DetNet
information. In the scope of DetNet, packet processing delay, which begins
after the packet goes into the input port and ends before the packet
arrives the output buffer, can expected in a known range, and the
value of the delay bound is specified in this sub-TLV,
including:Maximum DetNet packet processing delayMinimum DetNet packet processing delayMaximum DetNet packet processing delay variationThe format of this sub-TLV is shown in the following
diagram:The Type field is 1 octets in length, and the value is TBD1.The Length field is 1 octets in length and its value is 8.The RESERVED field is reserved for future use. It MUST be set to
0 when sent and MUST be ignored when received.The Minimum DetNet Processing Delay is 3 octets in length and
presents the minimum delay for a DetNet flow in the device,
excluding the queuing delay in output port. The units are
microsecond.The Maximum DetNet Processing Delay is 3 octets in length and
presents the maximum delay for a DetNet flow in the device,
excluding the queuing delay in output port. The units are
microsecond.The Maximum DetNet Processing Delay Variation is 3 octets in
length and presents the maximum delay variation for a DetNet flow in
the device, excluding the queuing delay in output port. The units
are microsecond.This document defines new IS-IS TE sub-TLVs that can be announced
in the TLVs 22, 23, 141, 222, and 223 in order to distribute DetNet
information.This sub-TLV specifies the maximum amount of bandwidth that is
reserved for DetNet on this link. Note that this value SHOULD be
smaller than the value of Maximum Reservable
Link Bandwidth.The format of this sub-TLV is shown in the following diagram:The Type field is 1 octets in length, and the value is TBD2.The Length field is 1 octets in length and its value is 4.The RESERVED field is reserved for future use. It MUST be set to
0 when sent and MUST be ignored when received.This Maximum DetNet Reservable Bandwidth field is 3 octets in
length and presents the maximum bandwidth that may be reserved for
DetNet. The units are bytes per second.This sub-TLV specifies the available bandwidth that can be
reserved for DetNet flow on this link for now. It is different from
the Unreserved Bandwidth sub-TLV defined in referring to section 3.3.The format of this sub-TLV is shown in the following diagram:The Type field is 1 octets in length, and the value is TBD3.The Length field is 1 octets in length and its value is 4.The RESERVED field is reserved for future use. It MUST be set to
0 when sent and MUST be ignored when received.This Available DetNet Bandwidth field is 3 octets in length and
presents the available bandwidth for DetNet in this link. The units
are bytes per second.Time resource ID represent different types of identifiers used to
indicate the capability of underlying bounded latency mechanisms.
When the underlying technique is a logical queue based scheduling
mechanisms, it represents a queue ID (There may different
technologies for implementing logical queues, for example QoS,
Flex-E, etc.). When the underlying technique is a time scheduling
based mechanisms, it represents a time slot ID.(Cyclic queuing
mechanisms could be considered as a special form of time scheduling,
whose time slot is with equal length)There are 2 types of Time Resource Sub-TLV: Time Resource for
Logical queues sub-TLV and Time Resource for Time Scheduling
sub-TLV:The format of Time Resource for Logical queues sub-TLV is shown
in the following diagram:The Type field is 1 octets in length, and the value is TBD4.The Length field is 1 octets in length and its value is 24.Time resource ID for Logical Queues is 3 octets in length, and
specifies the identifier of a logical queue.The queue The Queue Buffer Size field is 3 octets in length, and
specifies the size of a queue with unit of bytes.Queue Bandwidth Volume: is 3 octets in length, and carries
maximum bandwidth could be put into the queue to provide the latency
boundary. It is encoded in G bps encoded as an integer value.Minimum Queuing Delay is 3 octets in length, and carries minimum
queuing delay value (in microseconds) encoded as an integer value.
Maximum Queuing Delay is 3 octets in length, and carries the
maximum queuing delay value (in microseconds) encoded as an integer
value. Maximum Queuing Delay variation is 3 octets in length, and
carries the maximum queuing delay variation value (in microseconds)
encoded as an integer value.The RESERVED field is reserved for future use. It MUST be set to
0 when sent and MUST be ignored when received.The format of Time Resource for Time Scheduling sub-TLV is shown
in the following diagram:The Type field is 2 octets in length, and the value is TBD5.The Length field is 2 octets in length and its value is 16.Time Resource ID for Time Slot is 4 octets in length, and
specifies the identifier of a time slot.The Time Slot Length field is 3 octets in length, and specifies
the length of time slot value (in microseconds) encoded as an
integer value. When it is based on IEEE 802.1 Qch, time slot
granularity presents cycle length.The Time Slot Start Time field is 3 octets in length, and
specifies the start time of the time slot in the time scheduling (in
microseconds) encoded as an integer value.The Time Slot End Time field is 3 octets in length, and specifies
the end time of the time slot in the time scheduling (in
microseconds) encoded as an integer value.The RESERVED field is reserved for future use. It MUST be set to
0 when sent and MUST be ignored when received.IANA is requested to register the ISIS sub-TLVs defined in this
document in the sub-TLVs for Router Capability TLV registry.IANA is requested to register the ISIS sub-TLVs defined in this
document in the Sub-TLVs for TLVs 22, 23, 141, 222, and 223
registry.This document does not introduce security issues beyond those
discussed inand.MAC Bridges and VLANs (IEEE 802.1Q-2014)Enhancements for Scheduled TrafficCyclic Queuing and ForwardingAsynchronous Traffic Shaping