draft-ietf-rap-signaled-priority-01.txt   draft-ietf-rap-signaled-priority-02.txt 
Internet Draft Shai Herzog Internet Draft Shai Herzog
Expiration: July 1999 IPHighway Expiration: August 1999 IPHighway
File: draft-ietf-rap-signaled-priority-01.txt File: draft-ietf-rap-signaled-priority-02.txt
Signaled Preemption Priority Policy Element Signaled Preemption Priority Policy Element
January 22, 1999 February 13, 1999
Status of this Memo Status of this Memo
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Abstract Abstract
This document describes a preemption priority policy element for use by This document describes a preemption priority policy element for use
signaled policy based admission protocols (such as [RSVP] and [COPS]). by signaled policy based admission protocols (such as [RSVP] and
[COPS]).
Preemption priority defines a relative importance (rank) within the set Preemption priority defines a relative importance (rank) within the
of flows competing to be admitted into the network. Rather than set of flows competing to be admitted into the network. Rather than
admitting flows by order of arrival (First Come First Admitted) network admitting flows by order of arrival (First Come First Admitted)
nodes may consider priorities to preempt some previously admitted low network nodes may consider priorities to preempt some previously
priority flows in order to make room for a newer, high-priority flow. admitted low priority flows in order to make room for a newer, high-
priority flow.
Table of Contents Table of Contents
Abstract...............................................................1 Abstract.............................................................1
Table of Contents......................................................2 Table of Contents....................................................2
1.Introduction.........................................................3 1 Introduction.......................................................3
2.Scope and Applicability..............................................3 2 Scope and Applicability............................................3
3.Stateless Policy.....................................................4 3 Stateless Policy...................................................4
4.Policy Element Format................................................4 4 Policy Element Format..............................................4
5.Priority Merging Issues..............................................6 5 Priority Merging Issues............................................6
5.1.Priority Merging Strategies........................................7 5.1 Priority Merging Strategies.....................................7
5.1.1.Take priority of highest QoS.....................................7 5.1.1 Take priority of highest QoS...................................7
5.1.2.Take highest priority............................................7 5.1.2 Take highest priority..........................................7
5.1.3.Force error on heterogeneous merge...............................8 5.1.3 Force error on heterogeneous merge.............................8
5.2.Modifying Priority Elements........................................8 5.2 Modifying Priority Elements.....................................8
6.Error Processing.....................................................9 6 Error Processing...................................................9
7.Security Considerations..............................................9 7 Security Considerations............................................9
8.References..........................................................10 8 References........................................................10
9.Author Information..................................................10 9 Author Information................................................10
A.Appendix: Example...................................................11 Appendix A: Example.................................................11
A.1.Computing Merged Priority.........................................11 A.1 Computing Merged Priority......................................11
A.2.Translation (Compression) of Priority Elements....................11 A.2 Translation (Compression) of Priority Elements.................11
1. Introduction 1 Introduction
Traditional Capacity based Admission Control (CAC) indiscriminately Traditional Capacity based Admission Control (CAC) indiscriminately
admits new flows until capacity is exhausted (First Come First admits new flows until capacity is exhausted (First Come First
Admitted). Policy based Admission Control (PAC) on the other hand Admitted). Policy based Admission Control (PAC) on the other hand
attempts to minimize the significance of order of arrival and use attempts to minimize the significance of order of arrival and use
policy based admission criteria instead. policy based admission criteria instead.
One of the more popular policy criteria is the rank of importance of a One of the more popular policy criteria is the rank of importance of
flow relative to the others competing for admission into a network a flow relative to the others competing for admission into a network
node. Preemption Priority takes effect only when a set of flows node. Preemption Priority takes effect only when a set of flows
attempting admission through a node represents overbooking of resources attempting admission through a node represents overbooking of
such that based on CAC some would have to be rejected. Preemption resources such that based on CAC some would have to be rejected.
priority criteria help the node select the most important flows Preemption priority criteria help the node select the most important
(highest priority) for admission, while rejecting the low priority flows (highest priority) for admission, while rejecting the low
ones. priority ones.
Network nodes which support preemption should consider priorities to Network nodes which support preemption should consider priorities to
preempt some previously admitted low-priority flows in order to make preempt some previously admitted low-priority flows in order to make
room for a newer, high-priority flow. room for a newer, high-priority flow.
This document describes the format and applicability of the preemption This document describes the format and applicability of the
priority represented as a policy element in [RSVP-EXT]. preemption priority represented as a policy element in [RSVP-EXT].
2. Scope and Applicability 2 Scope and Applicability
The Framework document for policy-based admission control [RAP] The Framework document for policy-based admission control [RAP]
describes the various components that participate in policy decision describes the various components that participate in policy decision
making (i.e., PDP, PEP and LPD). The emphasis of PREEMPTION_PRI making (i.e., PDP, PEP and LDP). The emphasis of PREEMPTION_PRI
elements is to be simple, stateless, and light-weight such that they elements is to be simple, stateless, and light-weight such that they
could be implemented internally within a node’s LDP (Local Decision could be implemented internally within a node’s LDP (Local Decision
Point). Point).
Certain base assumptions are made in the usage model for PREEMPTION_PRI Certain base assumptions are made in the usage model for
elements: PREEMPTION_PRI elements:
- They are created by PDPs - They are created by PDPs
In a model where PDPs control PEPs at the periphery of the policy In a model where PDPs control PEPs at the periphery of the policy
domain (e.g., in border routers), PDPs reduce sets of relevant domain (e.g., in border routers), PDPs reduce sets of relevant
policy rules into a single priority criterion. This priority as policy rules into a single priority criterion. This priority as
expressed in the PREEMPTION_PRI element can then be communicated to expressed in the PREEMPTION_PRI element can then be communicated
downstream PEPs of the same policy domain, which have LPDs but no to downstream PEPs of the same policy domain, which have LDPs but
controlling PDP. no controlling PDP.
- They can be processed by LDPs - They can be processed by LDPs
PREEMPTION_PRI elements are processed by LDPs of nodes that do not PREEMPTION_PRI elements are processed by LDPs of nodes that do not
have a controlling PDP. LDPs may interpret these objects, forward have a controlling PDP. LDPs may interpret these objects, forward
them as is, or perform local merging to forward an equivalent merged them as is, or perform local merging to forward an equivalent
PREEMPTION_PRI policy element. LDPs must follow the merging strategy merged PREEMPTION_PRI policy element. LDPs must follow the merging
that was encoded by PDPs in the PREEMPTION_PRI objects. (Clearly, a strategy that was encoded by PDPs in the PREEMPTION_PRI objects.
PDP, being a superset of LDP, may act as an LDP as well). (Clearly, a PDP, being a superset of LDP, may act as an LDP as
well).
- They are enforced by PEPs - They are enforced by PEPs
PREEMPTION_PRI elements interact with a node’s traffic control PREEMPTION_PRI elements interact with a node’s traffic control
module (and capacity admission control) to enforce priorities, and module (and capacity admission control) to enforce priorities, and
preempt previously admitted flows when the need arises. preempt previously admitted flows when the need arises.
3. Stateless Policy 3 Stateless Policy
Signaled Preemption Priority is stateless (does not require past Signaled Preemption Priority is stateless (does not require past
history or external information to be interpreted). Therefore, when history or external information to be interpreted). Therefore, when
carried in COPS messages for the outsourcing of policy decisions, these carried in COPS messages for the outsourcing of policy decisions,
objects are included as COPS Stateless Policy Data Decision objects these objects are included as COPS Stateless Policy Data Decision
(see [COSP, COPS-RSVP]). objects (see [COSP, COPS-RSVP]).
4. Policy Element Format 4 Policy Element Format
The format of Policy Data objects is defined in [RSVP-EXT]. A single The format of Policy Data objects is defined in [RSVP-EXT]. A single
Policy Data object may contain one or more policy elements, each Policy Data object may contain one or more policy elements, each
representing a different (and perhaps orthogonal) policy. representing a different (and perhaps orthogonal) policy.
The format of preemption priority policy element is as follows: The format of preemption priority policy element is as follows:
+-------------+-------------+-------------+-------------+ +-------------+-------------+-------------+-------------+
| Length (12) | P-Type = PREEMPTION_PRI | | Length (12) | P-Type = PREEMPTION_PRI |
+------+------+-------------+-------------+-------------+ +------+------+-------------+-------------+-------------+
skipping to change at page 5, line 38 skipping to change at page 5, line 38
0 NO_ERROR Value used for regular PREEMPTION_PRI elements 0 NO_ERROR Value used for regular PREEMPTION_PRI elements
1 PREEMPTION This previously admitted flow was preempted 1 PREEMPTION This previously admitted flow was preempted
2 HETEROGENEOUS This element encountered heterogeneous merge 2 HETEROGENEOUS This element encountered heterogeneous merge
Reserved: 8 bits Reserved: 8 bits
Always 0. Always 0.
Preemption Priority: 16 bit (unsigned) Preemption Priority: 16 bit (unsigned)
The priority of the new flow compared with the defending priority of The priority of the new flow compared with the defending priority
previously admitted flows. Higher values represent higher Priority. of previously admitted flows. Higher values represent higher
Priority.
Defending Priority: 16 bits (unsigned) Defending Priority: 16 bits (unsigned)
Once a flow was admitted, the preemption priority becomes Once a flow was admitted, the preemption priority becomes
irrelevant. Instead, its defending priority is used to compare with irrelevant. Instead, its defending priority is used to compare
the preemption priority of new flows. with the preemption priority of new flows.
For any specific flow, its preemption priority must always be less For any specific flow, its preemption priority must always be less
than or equal to the defending priority. A wide gap between than or equal to the defending priority. A wide gap between
preemption and defending priority provides added stability: moderate preemption and defending priority provides added stability:
preemption priority makes it harder for a flow to preempt others, moderate preemption priority makes it harder for a flow to preempt
but once it succeeded, the higher defending priority makes it easier others, but once it succeeded, the higher defending priority makes
for the flow to avoid preemption itself. This provides a mechanism it easier for the flow to avoid preemption itself. This provides a
for balancing between order dependency and priority. mechanism for balancing between order dependency and priority.
5. Priority Merging Issues 5 Priority Merging Issues
Consider the case where two RSVP reservations merge: Consider the case where two RSVP reservations merge:
F1: QoS=High, Priority=Low F1: QoS=High, Priority=Low
F2: QoS=Low, Priority=High F2: QoS=Low, Priority=High
F1+F2= F3: QoS=High, Priority=??? F1+F2= F3: QoS=High, Priority=???
The merged reservation F3 should have QoS=Hi, but what Priority should The merged reservation F3 should have QoS=Hi, but what Priority
it assume? Several negative side-effects have been identified that may should it assume? Several negative side-effects have been identified
affect such a merger: that may affect such a merger:
Free-Riders: Free-Riders:
If F3 assumes Priority=High, then F1 got a free ride, assuming high If F3 assumes Priority=High, then F1 got a free ride, assuming high
priority that was only intended to the low QoS F2. If one associates priority that was only intended to the low QoS F2. If one associates
costs as a function of QoS and priority, F1 receives an “expensive” costs as a function of QoS and priority, F1 receives an “expensive”
priority without having to “pay” for it. priority without having to “pay” for it.
Denial of Service: Denial of Service:
If F3 assumes Priority=Low, the merged flow could be preempted or fail If F3 assumes Priority=Low, the merged flow could be preempted or
even though F2 presented high priority. fail even though F2 presented high priority.
Denial of service is virtually the inverse of the free-rider problem. Denial of service is virtually the inverse of the free-rider
When flows compete for resources, if one flow receives undeserving high problem. When flows compete for resources, if one flow receives
priority it may be able to preempt another deserving flow (hence one undeserving high priority it may be able to preempt another
free-rider turns out to be another’s denial of service). deserving flow (hence one free-rider turns out to be another’s
denial of service).
Instability: Instability:
The combination of preemption priority, killer reservation and blockade The combination of preemption priority, killer reservation and
state [RSVP] may increase the instability of admitted flows where a blockade state [RSVP] may increase the instability of admitted flows
reservation may be preempted, reinstated, and preempted again where a reservation may be preempted, reinstated, and preempted
periodically. again periodically.
5.1. Priority Merging Strategies .1 Priority Merging Strategies
In merging situations LDPs may receive multiple preemption elements In merging situations LDPs may receive multiple preemption elements
and must compute the priority of the merged flow according to the and must compute the priority of the merged flow according to the
following rules: following rules:
a. Preemption priority and defending priority are merged and computed a. Preemption priority and defending priority are merged and
separately, irrespective of each other. computed separately, irrespective of each other.
b. Participating priority elements are selected. b. Participating priority elements are selected.
All priority elements are examined according to their merging All priority elements are examined according to their merging
strategy to decide whether they should participate in the merged strategy to decide whether they should participate in the merged
result (as specified bellow). result (as specified bellow).
c. The highest priority of all participating priority elements is c. The highest priority of all participating priority elements is
computed. computed.
The remainder of this section describes the different merging The remainder of this section describes the different merging
strategies the can be specified in the PREEMPTION_PRI element. strategies the can be specified in the PREEMPTION_PRI element.
5.1.1. Take priority of highest QoS 1.1 Take priority of highest QoS
The PREEMPTION_PRI element would participate in the merged reservation The PREEMPTION_PRI element would participate in the merged
only if it belongs to a flow that contributed to the merged QoS level reservation only if it belongs to a flow that contributed to the
(i.e., that its QoS requirement does not constitute a subset another merged QoS level (i.e., that its QoS requirement does not constitute
reservation.) a subset another reservation.)
A simple way to determine whether a flow contributed to the merged QoS A simple way to determine whether a flow contributed to the merged
result is to compute the merged QoS with and without it and to compare QoS result is to compute the merged QoS with and without it and to
the results (although this is clearly not the most efficient method). compare the results (although this is clearly not the most efficient
method).
The reasoning for this approach is that the highest QoS flow is the one The reasoning for this approach is that the highest QoS flow is the
dominating the merged reservation and as such its priority should one dominating the merged reservation and as such its priority
dominate it as well. This approach is the most amiable to the should dominate it as well. This approach is the most amiable to the
prevention of priority distortions such as free-riders and denial of prevention of priority distortions such as free-riders and denial of
service. service.
This is a recommended merging strategy. This is a recommended merging strategy.
5.1.2. Take highest priority 1.2 Take highest priority
All PREEMPTION_PRI elements participate in the merged reservation. All PREEMPTION_PRI elements participate in the merged reservation.
This strategy disassociates priority and QoS level, and therefore is This strategy disassociates priority and QoS level, and therefore is
highly subject to free-riders and its inverse image, denial of service. highly subject to free-riders and its inverse image, denial of
service.
This is not a recommended method, but may be simpler to implement. This is not a recommended method, but may be simpler to implement.
5.1.3. Force error on heterogeneous merge 1.3 Force error on heterogeneous merge
A PREEMPTION_PRI element may participate in a merged reservation only A PREEMPTION_PRI element may participate in a merged reservation
if all other flows in the merged reservation have the same QoS level only if all other flows in the merged reservation have the same QoS
(heterogeneous flows). level (homogeneous flows).
The reasoning for this approach assumes that the heterogeneous case is The reasoning for this approach assumes that the heterogeneous case
relatively rare and too complicated to deal with, thus it better be is relatively rare and too complicated to deal with, thus it better
prohibited. be prohibited.
This strategy lends itself to denial of service, when a single receiver This strategy lends itself to denial of service, when a single
specifying a non-compatible QoS level may cause denial of service for receiver specifying a non-compatible QoS level may cause denial of
all other receivers of the merged reservation. service for all other receivers of the merged reservation.
Note: The determination of heterogeneous flows applies to QoS level Note: The determination of heterogeneous flows applies to QoS level
only (FLOWSPEC values), and is a matter for local (LDP) definition. only (FLOWSPEC values), and is a matter for local (LDP) definition.
Other types of heterogeneous reservations (e.g. conflicting reservation Other types of heterogeneous reservations (e.g. conflicting
styles) are handled by RSVP and are unrelated to this PREEMPTION_PRI reservation styles) are handled by RSVP and are unrelated to this
element. PREEMPTION_PRI element.
5.2. Modifying Priority Elements .2 Modifying Priority Elements
When POLICY_DATA objects are protected by integrity, LDPs should not When POLICY_DATA objects are protected by integrity, LDPs should not
attempt to modify them. They must be forwarded as-is or else their attempt to modify them. They must be forwarded as-is or else their
security envelope would be invalidated. In other cases, LDPs may modify security envelope would be invalidated. In other cases, LDPs may
and merge incoming PREEMPTION_PRI elements to reduce their size and modify and merge incoming PREEMPTION_PRI elements to reduce their
number according to the following rule: size and number according to the following rule:
- Merging is performed for each merging strategy separately. - Merging is performed for each merging strategy separately.
There is no known algorithm to merge PREEMPTION_PRI element of There is no known algorithm to merge PREEMPTION_PRI element of
different merging strategies without loosing valuable information different merging strategies without loosing valuable information
that may affect OTHER nodes. that may affect OTHER nodes.
- For each merging strategy, the highest QoS of all participating - For each merging strategy, the highest QoS of all participating
PREEMPTION_PRI elements is taken and is placed in an outgoing PREEMPTION_PRI elements is taken and is placed in an outgoing
PREEMPTION_PRI element of this merging strategy. PREEMPTION_PRI element of this merging strategy.
This approach effectively compresses the number of forwarded This approach effectively compresses the number of forwarded
PREEMPTION_PRI elements to at most to the number of different merging PREEMPTION_PRI elements to at most to the number of different
strategies, regardless of the number of receivers (See the example in merging strategies, regardless of the number of receivers (See the
Appendix A.2). example in Appendix A.2).
6. Error Processing 6 Error Processing
A PREEMPTION_PRI error object is sent back toward the appropriate A PREEMPTION_PRI error object is sent back toward the appropriate
receivers when an error involving PREEMPTION_PRI elements occur. receivers when an error involving PREEMPTION_PRI elements occur.
PREEMPTION PREEMPTION
When a previously admitted flow is preempted, a copy of the preempting When a previously admitted flow is preempted, a copy of the
flow’s PREEMPTION_PRI element is sent back toward the PDP that preempting flow’s PREEMPTION_PRI element is sent back toward the PDP
originated the preempted PREEMPTION_PRI object. This PDP, having that originated the preempted PREEMPTION_PRI object. This PDP,
information on both the preempting and the preempted priorities may having information on both the preempting and the preempted
construct a higher priority PREEMPTION_PRI element in an effort to re- priorities may construct a higher priority PREEMPTION_PRI element in
instate the preempted flow. an effort to re-instate the preempted flow.
Heterogeneity Heterogeneity
When a flow F1 with Heterogeneous Error merging strategy set in its When a flow F1 with Heterogeneous Error merging strategy set in its
PREEMPTION_PRI element encounters heterogeneity the PREEMPTION_PRI PREEMPTION_PRI element encounters heterogeneity the PREEMPTION_PRI
element is sent back toward receivers with the Heterogeneity error code element is sent back toward receivers with the Heterogeneity error
set. code set.
7. Security Considerations 7 Security Considerations
The integrity of PREEMPTION_PRI is guaranteed, as any other policy The integrity of PREEMPTION_PRI is guaranteed, as any other policy
element, by the encapsulation into a Policy Data object [RSVP-EXT]. element, by the encapsulation into a Policy Data object [RSVP-EXT].
Further security mechanisms are not warranted, especially considering Further security mechanisms are not warranted, especially
that preemption priority aims to provide simple and quick guidance to considering that preemption priority aims to provide simple and
routers within a trusted zone or at least a single zone (no zone quick guidance to routers within a trusted zone or at least a single
boundaries are crossed). zone (no zone boundaries are crossed).
8. References 8 References
[RSVP-EXT] Herzog, S. "RSVP Extensions for Policy Control", Internet- [RSVP-EXT] Herzog, S. "RSVP Extensions for Policy Control",
Draft, draft-ietf-rap-rsvp-ext-02.txt, Jan. 1999. Internet-Draft, draft-ietf-rap-rsvp-ext-02.txt, Jan. 1999.
[COPS-RSVP] Boyle, J., Cohen, R., Durham, D., Herzog, S., Raja,n R., [COPS-RSVP] Boyle, J., Cohen, R., Durham, D., Herzog, S., Raja,n
Sastry, A., “COPS usage for RSVP” Internet-Draft, draft-ietf- R., Sastry, A., “COPS usage for RSVP” Internet-Draft, draft-
rap-cops-rsvp-02.txt, Jan 1999. ietf-rap-cops-rsvp-02.txt, Jan 1999.
[RAP] Yavatkar, R., et al., "A Framework for Policy Based Admission [RAP] Yavatkar, R., et al., "A Framework for Policy Based
Control",IETF <draft-ietf-rap-framework-02.txt>, Jan., 1999. Admission Control",IETF <draft-ietf-rap-framework-02.txt>,
Jan., 1999.
[COPS] Boyle, J., Cohen, R., Durham, D., Herzog, S., Raja,n R., [COPS] Boyle, J., Cohen, R., Durham, D., Herzog, S., Raja,n R.,
Sastry, A., "The COPS (Common Open Policy Service) Protocol", Sastry, A., "The COPS (Common Open Policy Service) Protocol",
IETF <draft-ietf-rap-cops-05.txt>, Jan. 1999. IETF <draft-ietf-rap-cops-05.txt>, Jan. 1999.
[RSVP] Braden, R. ed., "Resource ReSerVation Protocol (RSVP) - [RSVP] Braden, R. ed., "Resource ReSerVation Protocol (RSVP) -
Functional Specification.", IETF RFC 2205, Proposed Standard, Functional Specification.", IETF RFC 2205, Proposed Standard,
Sep. 1997. Sep. 1997.
9. Author Information 9 Author Information
Shai Herzog, IPHighway Shai Herzog, IPHighway
Parker Plaza, Suite 1500 Parker Plaza, Suite 1500
400 Kelby St. 400 Kelby St.
Fort-Lee, NJ 07024 Fort-Lee, NJ 07024
(201) 585-0800 (201) 585-0800
herzog@iphighway.com herzog@iphighway.com
A. Appendix: Example Appendix A: Example
The following examples describe the computation of merged priority The following examples describe the computation of merged priority
elements as well as the translation (compression) of PREEMPTION_PRI elements as well as the translation (compression) of PREEMPTION_PRI
elements. elements.
A.1. Computing Merged Priority A.1 Computing Merged Priority
r1 r1
/ QoS=Hi (Pr=3, St=Highest QoS) / QoS=Hi (Pr=3, St=Highest QoS)
/ /
s1-----A---------B--------r2 QoS=Low (Pr=4, St=Highest PP) s1-----A---------B--------r2 QoS=Low (Pr=4, St=Highest PP)
\ \ \ \
\ \ QoS=Low (Pr=7, St=Highest QoS) \ \ QoS=Low (Pr=7, St=Highest QoS)
r4 r3 r4 r3
QoS=Low (Pr=9, St=Error) QoS=Low (Pr=9, St=Error)
Example 1: Merging preemption priority elements Example 1: Merging preemption priority elements
Example one describes a multicast scenario with one sender and four Example one describes a multicast scenario with one sender and four
receivers each with each own PREEMPTION_PRI element definition. receivers each with each own PREEMPTION_PRI element definition.
r1, r2 and r3 merge in B. The resulting priority is 4. r1, r2 and r3 merge in B. The resulting priority is 4.
Reason: The PREEMPTION_PRI of r3 doesn’t participate (since r3 is not Reason: The PREEMPTION_PRI of r3 doesn’t participate (since r3 is
contributing to the merged QoS) and the priority is the highest of the not contributing to the merged QoS) and the priority is the highest
PREEMPTION_PRI from r1 and r2. of the PREEMPTION_PRI from r1 and r2.
r1, r2, r3 and r4 merge in A. The resulting priority is again 4: r4 r1, r2, r3 and r4 merge in A. The resulting priority is again 4: r4
doesn’t participate because its own QoS=Low is incompatible with the doesn’t participate because its own QoS=Low is incompatible with the
other (r1) QoS=High. An error PREEMPTION_PRI should be sent back to r4 other (r1) QoS=High. An error PREEMPTION_PRI should be sent back to
telling it that its PREEMPTION_PRI element encountered heterogeneity. r4 telling it that its PREEMPTION_PRI element encountered
heterogeneity.
A.2. Translation (Compression) of Priority Elements A.2 Translation (Compression) of Priority Elements
Given this set of participating PREEMPTION_PRI elements, the following Given this set of participating PREEMPTION_PRI elements, the
compression can take place at the merging node: following compression can take place at the merging node:
From: From:
(Pr=3, St=Highest QoS) (Pr=3, St=Highest QoS)
(Pr=7, St=Highest QoS) (Pr=7, St=Highest QoS)
(Pr=4, St=Highest PP) (Pr=4, St=Highest PP)
(Pr=9, St=Highest PP) (Pr=9, St=Highest PP)
(Pr=6, St=Highest PP) (Pr=6, St=Highest PP)
To: To:
(Pr=7, St=Highest QoS) (Pr=7, St=Highest QoS)
(Pr=9, St=Highest PP) (Pr=9, St=Highest PP)
 End of changes. 

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