draft-ietf-ccamp-rsvp-te-bandwidth-availability-03.txt   draft-ietf-ccamp-rsvp-te-bandwidth-availability-04.txt 
Network Working Group H. Long, M. Ye Network Working Group H. Long, M. Ye
Internet Draft Huawei Technologies Co., Ltd Internet Draft Huawei Technologies Co., Ltd
Intended status: Standards Track G. Mirsky Intended status: Standards Track G. Mirsky
Ericsson Ericsson
A.D'Alessandro A.D'Alessandro
Telecom Italia S.p.A Telecom Italia S.p.A
H. Shah H. Shah
Ciena Ciena
Expires: April 13, 2016 October 16, 2015 Expires: August 2016 February 19, 2016
Ethernet Traffic Parameters with Availability Information Ethernet Traffic Parameters with Availability Information
draft-ietf-ccamp-rsvp-te-bandwidth-availability-03.txt draft-ietf-ccamp-rsvp-te-bandwidth-availability-04.txt
Abstract Abstract
A Packet switching network may contain links with variable bandwidth, A Packet switching network may contain links with variable bandwidth,
e.g., copper, radio, etc. The bandwidth of such links is sensitive e.g., copper, radio, etc. The bandwidth of such links is sensitive
to external environment. Availability is typically used for to external environment. Availability is typically used for
describing the link during network planning. This document describing the link during network planning. This document
introduces an Extended Ethernet Bandwidth Profile TLV and an introduces an optional Availability TLV in Resource ReSerVation
optional Availability sub-TLV in Resource ReSerVation Protocol - Protocol -- Traffic Engineer (RSVP-TE) signaling. This extension can
Traffic Engineer (RSVP-TE) signaling. This extension can be used to be used to set up a label switching path (LSP) in a Packet Switched
set up a label switching path (LSP) in a Packet Switched Network Network (PSN) that contains links with discretely variable bandwidth.
(PSN) that contains links with discretely variable bandwidth.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
skipping to change at page 2, line 4 skipping to change at page 1, line 46
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other documents months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than as "work in progress." reference material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html
This Internet-Draft will expire on April 13, 2016.
This Internet-Draft will expire on August 19, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with carefully, as they describe your rights and restrictions with
respect to this document. Code Components extracted from this respect to this document. Code Components extracted from this
document must include Simplified BSD License text as described in document must include Simplified BSD License text as described in
Section 4.e of the Trust Legal Provisions and are provided without Section 4.e of the Trust Legal Provisions and are provided without
warranty as described in the Simplified BSD License. warranty as described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction ................................................ 3 1. Introduction ................................................ 3
2. Overview .................................................... 4 2. Overview .................................................... 4
3. Extension to RSVP-TE Signaling............................... 4 3. Extension to RSVP-TE Signaling............................... 4
3.1.1. Extended Ethernet Bandwidth Profile TLV............ 5 3.1. Availability TLV........................................ 4
3.1.2. Availability sub-TLV............................... 5 3.2. Signaling Process....................................... 5
3.2. FLOWSPEC Object......................................... 6 4. Security Considerations...................................... 6
3.3. Signaling Process....................................... 6 5. IANA Considerations ......................................... 6
4. Security Considerations...................................... 7 5.1 Ethernet Sender TSpec TLVs ............................. 6
5. IANA Considerations ......................................... 7 6. References .................................................. 7
5.1 Ethernet Sender TSpec TLVs ............................. 7 6.1. Normative References.................................... 7
5.2 Extended Ethernet Bandwidth Profile TLV ................ 8 6.2. Informative References.................................. 7
6. References .................................................. 8 7. Appendix: Bandwidth Availability Example..................... 8
6.1. Normative References.................................... 8 8. Acknowledgments ............................................. 9
6.2. Informative References.................................. 9
7. Appendix: Bandwidth Availability Example..................... 9
8. Acknowledgments ............................................ 11
Conventions used in this document Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119]. document are to be interpreted as described in RFC-2119 [RFC2119].
The following acronyms are used in this draft: The following acronyms are used in this draft:
RSVP-TE Resource Reservation Protocol-Traffic Engineering RSVP-TE Resource Reservation Protocol-Traffic Engineering
skipping to change at page 3, line 31 skipping to change at page 3, line 27
describe the link capacity during network planning. The availability describe the link capacity during network planning. The availability
is a time scale that the requested bandwidth is ensured. A more is a time scale that the requested bandwidth is ensured. A more
detailed example on the bandwidth availability can be found in detailed example on the bandwidth availability can be found in
Appendix A. Assigning different availability classes to different Appendix A. Assigning different availability classes to different
types of service over such kind of links provides more efficient types of service over such kind of links provides more efficient
planning of link capacity. To set up an LSP across these links, planning of link capacity. To set up an LSP across these links,
availability information is required for the nodes to verify availability information is required for the nodes to verify
bandwidth satisfaction and make bandwidth reservation. The bandwidth satisfaction and make bandwidth reservation. The
availability information should be inherited from the availability availability information should be inherited from the availability
requirements of the services expected to be carried on the LSP. For requirements of the services expected to be carried on the LSP. For
example, voice service usually needs "five nines" availability, example, voice service usually needs ''five nines'' availability,
while non-real time services may adequately perform at four or three while non-real time services may adequately perform at four or three
nines availability. Since different service types may need different nines availability. Since different service types may need different
availabilities guarantees, multiple <availability, bandwidth> pairs availabilities guarantees, multiple <availability, bandwidth> pairs
may be required when signaling. may be required when signaling.
If the availability requirement is not specified in the signaling If the availability requirement is not specified in the signaling
message, the bandwidth will be reserved as the highest availability. message, the bandwidth will be reserved as the highest availability.
For example, the bandwidth with 99.999% availability of a link is For example, the bandwidth with 99.999% availability of a link is
100 Mbps; the bandwidth with 99.99% availability is 200 Mbps. When a 100 Mbps; the bandwidth with 99.99% availability is 200 Mbps. When a
video application requests for 120 Mbps without availability video application requests for 120 Mbps without availability
requirement, the system will consider the request as 120 Mbps with requirement, the system will consider the request as 120 Mbps with
99.999% availability, while the available bandwidth with 99.999% 99.999% availability, while the available bandwidth with 99.999%
availability is only 100 Mbps, therefore the LSP path cannot be set availability is only 100 Mbps, therefore the LSP path cannot be set
up. But in fact, video application doesn't need 99.999% availability; up. But in fact, video application doesn't need 99.999% availability;
99.99% availability is enough. In this case, the LSP could be set up 99.99% availability is enough. In this case, the LSP could be set up
if availability is specified in the signaling message. if availability is specified in the signaling message.
To fulfill LSP setup by signaling in these scenarios, this document To fulfill LSP setup by signaling in these scenarios, this document
specifies an Extended Ethernet Bandwidth Profile and an Availability specifies an Availability TLV. The Availability TLV can be
sub-TLV. The Availability sub-TLV can be applicable to any kind of applicable to any kind of physical links with variable discrete
physical links with variable discrete bandwidth, such as microwave bandwidth, such as microwave or DSL. Multiple Availability TLVs
or DSL. Multiple Extended Ethernet Bandwidth Profiles with different together with multiple Ethernet Bandwidth Profiles can be carried in
availability can be carried in the Ethernet SENDER_TSPEC object. the Ethernet SENDER_TSPEC object.
2. Overview 2. Overview
A PSN tunnel may span one or more links in a network. To setup a A PSN tunnel may span one or more links in a network. To setup a
label switching path (LSP), a node may collect link information label switching path (LSP), a node may collect link information
which is spread in routing message, e.g., OSPF TE LSA message, by which is spread in routing message, e.g., OSPF TE LSA message, by
network nodes to get to know about the network topology, and network nodes to get to know about the network topology, and
calculate out an LSP route based on the network topology, and send calculate out an LSP route based on the network topology, and send
the calculated LSP route to signaling to initiate a PATH/RESV the calculated LSP route to signaling to initiate a PATH/RESV
message for setting up the LSP. message for setting up the LSP.
skipping to change at page 4, line 43 skipping to change at page 4, line 39
When a node initiates a PATH/RESV signaling to set up an LSP, the When a node initiates a PATH/RESV signaling to set up an LSP, the
PATH message should carry the <bandwidth, availability> requirement PATH message should carry the <bandwidth, availability> requirement
list as bandwidth request. Intermediate node(s) will allocate the list as bandwidth request. Intermediate node(s) will allocate the
bandwidth resource for each availability requirement from the bandwidth resource for each availability requirement from the
remaining bandwidth with corresponding availability. An error remaining bandwidth with corresponding availability. An error
message may be returned if any <bandwidth, availability> request message may be returned if any <bandwidth, availability> request
cannot be satisfied. cannot be satisfied.
3. Extension to RSVP-TE Signaling 3. Extension to RSVP-TE Signaling
The initial idea is to define an Availability sub-TLV under Ethernet 3.1. Availability TLV
Bandwidth Profile TLV [RFC6003]. However the Ethernet Bandwidth
Profile TLV doesn't have the ability to carry a sub-TLV according to
RFC6003. Therefore, an Extend Ethernet Bandwidth Profile TLV is
defined in this document to avoid the backward compatibility issue.
The Extended Ethernet Bandwidth Profile TLV includes Ethernet BW TLV
and has variable length. It MAY include Availability sub-TLV which
is also defined in this document.
3.1.1. Extended Ethernet Bandwidth Profile TLV
The Extended Ethernet Bandwidth Profile TLV is included in the
Ethernet SENDER_TSPEC, and MAY be included for more than one time.
The Extended Ethernet Bandwidth Profile TLV has the following format.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Pro|A| | Index | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CIR |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CBS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| EIR |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| EBS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-TLV(OPTIONAL) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: A new "AF" filed in Extended Ethernet Bandwidth Profile TLV
The difference between the Extended Ethernet Bandwidth Profile TLV
and Ethernet Bandwidth Profile TLV is that a new AF field to
indicate the sub-TLV is defined in the Extended Ethernet Bandwidth
Profile TLV. The rest definitions are the same.
A new filed is defined in this document:
AF filed (bit 2): Availability Field (AF)
If the AF filed is set to 1, Availability sub-TLV MUST be included
in the Extended Ethernet Bandwidth Profile TLV. If the AF field is
set to value 0, then an Availability sub-TLV SHOULD NOT be included.
3.1.2. Availability sub-TLV
The Availability sub-TLV has the following format: An Availability TLV is defined as a TLV of the Ethernet
SENDEDR_TSPEC object [RFC6003] in this document. The Ethernet
SENDER_TSPEC object MAY include more than one Availability TLV. The
Availability TLV has the following format:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Index | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Availability | | Availability |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Availability sub-TLV Figure 1: Availability TLV
Type (2 octets): TBD Index (1 octet):
Length (2 octets): 4 The Availability TLV MUST come along with Ethernet Bandwidth
Profile TLV. If the bandwidth requirements in the multiple
Ethernet Bandwidth Profile TLVs have different Availability
requirements, multiple Availability TLVs SHOULD be carried. In
such a case, the Availability TLV has one to one correspondence
with Ethernet Bandwidth Profile TLV by having the same value of
Index field. If all the bandwidth requirements in the Ethernet
Bandwidth Profile have the same Availability requirement, one
Availability TLV SHOULD be carried. In this case, the Index field
is set to 0.
Reserved (3 octets): These bits SHOULD be set to zero when sent
and MUST be ignored when received.
Availability (4 octets): a 32-bit floating number describes the Availability (4 octets): a 32-bit floating number describes the
decimal value of availability requirement for this bandwidth decimal value of availability requirement for this bandwidth
request. The value MUST be less than 1. request. The value MUST be less than 1.
As the Extended Ethernet Bandwidth Profile TLV can be carried for 3.2. Signaling Process
one or more times in the Ethernet SENDER_TSPEC object, the
Availability sub-TLV can also be present for one or more times.
3.2. FLOWSPEC Object
The FLOWSPEC object (Class-Num = 9, Class-Type = TBD) has the same
format as the Ethernet SENDER_TSPEC object.
3.3. Signaling Process
The source node initiates PATH messages including one or more The source node initiates PATH messages which carry a number of
Extended Bandwidth Profile TLVs with different availability values bandwidth request information, including one or more Ethernet
in the SENDER_TSPEC object. Each Extended Bandwidth Profile TLV Bandwidth Profile TLVs and one or more Availability TLVs. Each
specifies the bandwidth request with referred availability Ethernet Bandwidth Profile TLV corresponds to an availability
requirement. parameter in the Availability TLV.
The intermediate and destination nodes check whether they can The intermediate and destination nodes check whether they can
satisfy the bandwidth requirements by comparing each bandwidth satisfy the bandwidth requirements by comparing each bandwidth
requirement inside the SENDER_TSPEC objects with the remaining link requirement inside the SENDER_TSPEC objects with the remaining link
sub-bandwidth resource with respective availability guarantee when sub-bandwidth resource with respective availability guarantee on the
received the PATH message. local link when received the PATH message.
o If all <bandwidth, availability> requirements can be o If all <bandwidth, availability> requirements can be
satisfied (the requested bandwidth under each availability satisfied (the requested bandwidth under each availability
parameter is smaller than or equal to the remaining bandwidth parameter is smaller than or equal to the remaining bandwidth
under the corresponding availability parameter on its local under the corresponding availability parameter on its local
link), it SHOULD reserve the bandwidth resource from each link), it SHOULD reserve the bandwidth resource from each
remaining sub-bandwidth portion on its local link to set up remaining sub-bandwidth portion on its local link to set up
this LSP. Optionally, the higher availability bandwidth can be this LSP. Optionally, the higher availability bandwidth can be
allocated to lower availability request when the lower allocated to lower availability request when the lower
availability bandwidth cannot satisfy the request. availability bandwidth cannot satisfy the request.
skipping to change at page 7, line 25 skipping to change at page 6, line 25
o If at least one <bandwidth, availability> requirement cannot o If at least one <bandwidth, availability> requirement cannot
be satisfied, it SHOULD generate PathErr message with the error be satisfied, it SHOULD generate PathErr message with the error
code "Admission Control Error" and the error value "Requested code "Admission Control Error" and the error value "Requested
Bandwidth Unavailable" (see [RFC2205]). Bandwidth Unavailable" (see [RFC2205]).
If two LSPs request for the bandwidth with the same availability If two LSPs request for the bandwidth with the same availability
requirement, a way to resolve the contention is comparing the node requirement, a way to resolve the contention is comparing the node
ID, the node with the higher node ID will win the contention. More ID, the node with the higher node ID will win the contention. More
details can be found in [RFC3473]. details can be found in [RFC3473].
If a node does not support the Extended Bandwidth Profile TLV and If a node does not support Availability TLV, it SHOULD generate
Availability sub-TLV, it SHOULD generate PathErr message with the PathErr message with the error code "Extended Class-Type Error" and
error code "Extended Class-Type Error" and the error value "Class- the error value "Class-Type mismatch" (see [RFC2205]).
Type mismatch" (see [RFC2205]).
4. Security Considerations 4. Security Considerations
This document does not introduce new security considerations to the This document does not introduce new security considerations to the
existing RSVP-TE signaling protocol. existing RSVP-TE signaling protocol.
5. IANA Considerations 5. IANA Considerations
IANA maintains registries and sub-registries for RSVP-TE used by IANA maintains registries and sub-registries for RSVP-TE used by
GMPLS. IANA is requested to make allocations from these registries GMPLS. IANA is requested to make allocations from these registries
as set out in the following sections. as set out in the following sections.
5.1 Ethernet Sender TSpec TLVs 5.1 Ethernet Sender TSpec TLVs
IANA maintains a registry of GMPLS parameters called "Generalized IANA maintains a registry of GMPLS parameters called ''Generalized
Multi-Protocol Label Switching (GMPLS) Signaling Parameters". Multi-Protocol Label Switching (GMPLS) Signaling Parameters''.
IANA has created a new sub-registry called "Ethernet Sender TSpec IANA has created a new sub-registry called ''Ethernet Sender TSpec
TLVs / Ethernet Flowspec TLVs" to contain the TLV type values for TLVs / Ethernet Flowspec TLVs'' to contain the TLV type values for
TLVs carried in the Ethernet SENDER_TSPEC object. A new value is as TLVs carried in the Ethernet SENDER_TSPEC object. A new type for
follow: Availability TLV is defined as follow:
Type Description Reference Type Description Reference
----- ----------------------------------- --------- ----- ----------------------------------- ---------
TBD Extended Ethernet Bandwidth Profile [This ID] TBD Availability [This ID]
5.2 Extended Ethernet Bandwidth Profile TLV
IANA has created a new sub-registry called "Extended Ethernet
Bandwidth Profiles" to contain bit flags carried in the Extended
Ethernet Bandwidth Profile TLV of the Ethernet SENDER_TSPEC object.
Bits are to be allocated by Standards Action. Bits are numbered from
bit 0 as the low order bit. A new bit field is as follow:
Bit Hex Description Reference
--- ---- ------------------ -----------
0 0x01 Coupling Flag (CF) [RFC6003]
1 0x02 Color Mode (CM) [RFC6003]
2 0x04 Availability Field (AF) [This ID]
Sub-TLV types for Extended Ethernet Bandwidth Profiles are to be
allocated by Standards Action. Initial values are as follows:
Type Length Format Description
--- ---- ------------------ -----------
0 - Reserved Reserved value
0x01 4 see Section 3.1.2 of this ID Availability
6. References 6. References
6.1. Normative References 6.1. Normative References
[RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP V.,and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001. Tunnels", RFC 3209, December 2001.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic (GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC6003] Papadimitriou, D. "Ethernet Traffic Parameters", RFC 6003, [RFC6003] Papadimitriou, D. ''Ethernet Traffic Parameters'', RFC 6003,
October 2010. October 2010.
6.2. Informative References 6.2. Informative References
[MCOS] Minei, I., Gan, D., Kompella, K., and X. Li, "Extensions [G.827] ITU-T Recommendation, ''Availability performance parameters
for Differentiated Services-aware Traffic Engineered
LSPs", Work in Progress, June 2006.
[G.827] ITU-T Recommendation, "Availability performance parameters
and objectives for end-to-end international constant bit- and objectives for end-to-end international constant bit-
rate digital paths", September, 2003. rate digital paths'', September, 2003.
[F.1703] ITU-R Recommendation, "Availability objectives for real [F.1703] ITU-R Recommendation, ''Availability objectives for real
digital fixed wireless links used in 27 500 km digital fixed wireless links used in 27 500 km
hypothetical reference paths and connections", January, hypothetical reference paths and connections'', January,
2005. 2005.
[P.530] ITU-R Recommendation," Propagation data and prediction [P.530] ITU-R Recommendation,'' Propagation data and prediction
methods required for the design of terrestrial line-of- methods required for the design of terrestrial line-of-
sight systems", February, 2012 sight systems'', February, 2012
[EN 302 217] ETSI standard, "Fixed Radio Systems; Characteristics [EN 302 217] ETSI standard, ''Fixed Radio Systems; Characteristics
and requirements for point-to-point equipment and and requirements for point-to-point equipment and
antennas", April, 2009 antennas'', April, 2009
[ARTE] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H., [ARTE] H., Long, M., Ye, Mirsky, G., Alessandro, A., Shah, H.,
"OSPF Routing Extension for Links with Variable Discrete ''OSPF Routing Extension for Links with Variable Discrete
Bandwidth", Work in Progress, June, 2015 Bandwidth'', Work in Progress, June, 2015
7. Appendix: Bandwidth Availability Example 7. Appendix: Bandwidth Availability Example
In mobile backhaul network, microwave links are very popular for In mobile backhaul network, microwave links are very popular for
providing connection of last hops. In case of heavy rain, to providing connection of last hops. In case of heavy rain, to
maintain the link connectivity, the microwave link MAY lower the maintain the link connectivity, the microwave link MAY lower the
modulation level since demodulating the lower modulation level needs modulation level since demodulating the lower modulation level needs
a lower Signal-to-Noise Ratio (SNR). This is called adaptive a lower Signal-to-Noise Ratio (SNR). This is called adaptive
modulation technology [EN 302 217]. However, a lower modulation modulation technology [EN 302 217]. However, a lower modulation
level also means lower link bandwidth. When link bandwidth is level also means lower link bandwidth. When link bandwidth is
 End of changes. 32 change blocks. 
162 lines changed or deleted 79 lines changed or added

This html diff was produced by rfcdiff 1.42. The latest version is available from http://tools.ietf.org/tools/rfcdiff/