IP Traffic Flow Security
draft-ietf-ipsecme-iptfs-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 9347.
|
|
|---|---|---|---|
| Author | Christian Hopps | ||
| Last updated | 2019-12-16 | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews |
GENART Last Call review
(of
-12)
by Peter Yee
Ready w/issues
|
||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 9347 (Proposed Standard) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-ipsecme-iptfs-00
D:
Don't Fragment bit, if set indicates the sender of the notify
message does not support receiving packet fragments (i.e., inner
packets MUST be sent using a single "Data Block"). This value
only applies to what the sender is capable of receiving; the
sender MAY still send packet fragments unless similarly restricted
by the receiver in it's IPTFS_REQUIREMENTS notification.
6. Packet and Data Formats
6.1. ESP IP-TFS Payload
An ESP IP-TFS payload is identified by the IP protocol number
IPTFS_PROTOCOL (TBD1). This payload begins with a fixed 4 or 16
octet header followed by a variable amount of "DataBlocks" data. The
exact payload format and fields are defined in the following
sections.
6.1.1. Non-Congestion Control IPTFS_PROTOCOL Payload Format
The non-congestion control IPTFS_PROTOCOL payload is comprised of a 4
octet header followed by a variable amount of "DataBlocks" data as
shown below.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V|C| Reserved | BlockOffset |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DataBlocks ...
+-+-+-+-+-+-+-+-+-+-+-
V:
A 1 bit version field that MUST be set to zero. If received as
one the packet MUST be dropped.
C:
A 1 bit value that MUST be set to 0 to indicate no congestion
control information is present.
Reserved:
A 14 bit field set to 0 and ignored on receipt.
BlockOffset:
A 16 bit unsigned integer counting the number of octets of
"DataBlocks" data before the start of a new data block.
"BlockOffset" can count past the end of the "DataBlocks" data in
which case all the "DataBlocks" data belongs to the previous data
Hopps Expires June 18, 2020 [Page 12]
Internet-Draft IP Traffic Flow Security December 2019
block being re-assembled. If the "BlockOffset" extends into
subsequent packets it continues to only count subsequent
"DataBlocks" data (i.e., it does not count subsequent packets
non-"DataBlocks" octets).
DataBlocks:
Variable number of octets that begins with the start of a data
block, or the continuation of a previous data block, followed by
zero or more additional data blocks.
6.1.2. Congestion Control IPTFS_PROTOCOL Payload Format
The congestion control IPTFS_PROTOCOL payload is comprised of a 16
octet header followed by a variable amount of "DataBlocks" data as
shown below.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V|C|E| Reserved | BlockOffset |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RTT | Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LossEventRate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LastSeqNum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DataBlocks ...
+-+-+-+-+-+-+-+-+-+-+-
V:
A 1 bit version field that MUST be set to zero. If received as
one the packet MUST be dropped.
C:
A 1 bit value that MUST be set to 1 which indicates the presence
of the congestion information header fields "RTT", "Delay",
"LossEventRate" and "LastSeqNum".
E:
A 1 bit value if set indicates that Congestion Experienced (CE)
ECN bits were received and used in deriving the reported
"LossEventRate".
Reserved:
A 13 bit field set to 0 and ignored on receipt.
BlockOffset:
Hopps Expires June 18, 2020 [Page 13]
Internet-Draft IP Traffic Flow Security December 2019
The same value as the non-congestion controlled payload format
value.
RTT:
A 16 bit value specifying the sender's current round-trip time
estimate in milliseconds. The value MAY be zero prior to the
sender having calculated a round-trip time estimate. The value
SHOULD be set to zero on non-IP-TFS enabled SAs.
Delay:
A 16 bit value specifying the delay in milliseconds incurred
between the receiver receiving the "LastSeqNum" packet and the
sending of this acknowledgement of it.
LossEventRate:
A 32 bit value specifying the inverse of the current loss event
rate as calculated by the receiver. A value of zero indicates no
loss. Otherwise the loss event rate is "1/LossEventRate".
LastSeqNum:
A 32 bit value containing the lower 32 bits of the largest
sequence number last received. This is the latest in the sequence
not necessarily the most recent (in the case of re-ordering of
packets it may be less recent). When determining largest and 64
bit extended sequence numbers are in use, the upper 32 bits should
be used during the comparison.
DataBlocks:
Variable number of octets that begins with the start of a data
block, or the continuation of a previous data block, followed by
zero or more additional data blocks. For the special case of
sending congestion control information on an non-IP-TFS enabled SA
this value MUST be empty (i.e., be zero octets long).
6.1.3. Data Blocks
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 | IPv4, IPv6 or pad...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type:
A 4 bit field where 0x0 identifies a pad data block, 0x4 indicates
an IPv4 data block, and 0x6 indicates an IPv6 data block.
Hopps Expires June 18, 2020 [Page 14]
Internet-Draft IP Traffic Flow Security December 2019
6.1.3.1. IPv4 Data Block
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x4 | IHL | TypeOfService | TotalLength |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Rest of the inner packet ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
These values are the actual values within the encapsulated IPv4
header. In other words, the start of this data block is the start of
the encapsulated IP packet.
Type:
A 4 bit value of 0x4 indicating IPv4 (i.e., first nibble of the
IPv4 packet).
TotalLength:
The 16 bit unsigned integer length field of the IPv4 inner packet.
6.1.3.2. IPv6 Data Block
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x6 | TrafficClass | FlowLabel |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TotalLength | Rest of the inner packet ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
These values are the actual values within the encapsulated IPv6
header. In other words, the start of this data block is the start of
the encapsulated IP packet.
Type:
A 4 bit value of 0x6 indicating IPv6 (i.e., first nibble of the
IPv6 packet).
TotalLength:
The 16 bit unsigned integer length field of the inner IPv6 inner
packet.
6.1.3.3. Pad Data Block
Hopps Expires June 18, 2020 [Page 15]
Internet-Draft IP Traffic Flow Security December 2019
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x0 | Padding ...
+-+-+-+-+-+-+-+-+-+-+-
Type:
A 4 bit value of 0x0 indicating a padding data block.
Padding:
extends to end of the encapsulating packet.
7. IANA Considerations
7.1. IPTFS_PROTOCOL Type
This document requests a protocol number IPTFS_PROTOCOL be allocated
by IANA from "Assigned Internet Protocol Numbers" registry for
identifying the IP-TFS ESP payload format.
Type:
TBD1
Description:
IP-TFS ESP payload format.
Reference:
This document
7.2. IKEv2 Transform Type TFS Type
This document requests an IKEv2 Transform Type "TFS Type" be
allocated by IANA from the "Transform Type Values" registry.
Type:
TBD2
Description:
TFS Type
Used In:
(optional in ESP)
Reference:
This document
Hopps Expires June 18, 2020 [Page 16]
Internet-Draft IP Traffic Flow Security December 2019
7.3. TFS Type Transform IDs Registry
This document requests a "Transform Type TBD3 - TFS Type Transform
IDs" registry be created. The registration procedure is Expert
Review. The initial values are as follows:
Number Name Reference
----------------------------------------
0 NONE This document
1 TFS_IPTFS_CC This document
2 TFS_IPTFS_NOCC This document
3-65535 Reserved This document
7.4. IPTFS_REQUIREMENTS Notify Message Status Type
This document requests a status type IPTFS_REQUIREMENTS be allocated
from the "IKEv2 Notify Message Types - Status Types" registry.
Value:
TBD3
Name:
IPTFS_REQUIREMENTS
Reference:
This document
8. Security Considerations
This document describes a mechanism to add Traffic Flow
Confidentiality to IP traffic. Use of this mechanism is expected to
increase the security of the traffic being transported. Other than
the additional security afforded by using this mechanism, IP-TFS
utilizes the security protocols [RFC4303] and [RFC7296] and so their
security considerations apply to IP-TFS as well.
As noted previously in Section 2.5.2, for TFC to be fully maintained
the encapsulated traffic flow should not be affecting network
congestion in a predictable way, and if it would be then non-
congestion controlled mode use should be considered instead.
9. References
9.1. Normative References
Hopps Expires June 18, 2020 [Page 17]
Internet-Draft IP Traffic Flow Security December 2019
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
Kivinen, "Internet Key Exchange Protocol Version 2
(IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
2014, <https://www.rfc-editor.org/info/rfc7296>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References
[AppCrypt]
Schneier, B., "Applied Cryptography: Protocols,
Algorithms, and Source Code in C", 11 2017.
[I-D.iab-wire-image]
Trammell, B. and M. Kuehlewind, "The Wire Image of a
Network Protocol", draft-iab-wire-image-01 (work in
progress), November 2018.
[IKEV2IANA]
IANA, "Internet Key Exchange Version 2 (IKEv2)
Parameters",
<http://www.iana.org/assignments/ikev2-parameters/>.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
DOI 10.17487/RFC0791, September 1981,
<https://www.rfc-editor.org/info/rfc791>.
[RFC1191] Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191,
DOI 10.17487/RFC1191, November 1990,
<https://www.rfc-editor.org/info/rfc1191>.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998,
<https://www.rfc-editor.org/info/rfc2474>.
Hopps Expires June 18, 2020 [Page 18]
Internet-Draft IP Traffic Flow Security December 2019
[RFC2914] Floyd, S., "Congestion Control Principles", BCP 41,
RFC 2914, DOI 10.17487/RFC2914, September 2000,
<https://www.rfc-editor.org/info/rfc2914>.
[RFC3168] Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
of Explicit Congestion Notification (ECN) to IP",
RFC 3168, DOI 10.17487/RFC3168, September 2001,
<https://www.rfc-editor.org/info/rfc3168>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC4342] Floyd, S., Kohler, E., and J. Padhye, "Profile for
Datagram Congestion Control Protocol (DCCP) Congestion
Control ID 3: TCP-Friendly Rate Control (TFRC)", RFC 4342,
DOI 10.17487/RFC4342, March 2006,
<https://www.rfc-editor.org/info/rfc4342>.
[RFC5348] Floyd, S., Handley, M., Padhye, J., and J. Widmer, "TCP
Friendly Rate Control (TFRC): Protocol Specification",
RFC 5348, DOI 10.17487/RFC5348, September 2008,
<https://www.rfc-editor.org/info/rfc5348>.
[RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black,
"Encapsulating MPLS in UDP", RFC 7510,
DOI 10.17487/RFC7510, April 2015,
<https://www.rfc-editor.org/info/rfc7510>.
[RFC8084] Fairhurst, G., "Network Transport Circuit Breakers",
BCP 208, RFC 8084, DOI 10.17487/RFC8084, March 2017,
<https://www.rfc-editor.org/info/rfc8084>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
[RFC8201] McCann, J., Deering, S., Mogul, J., and R. Hinden, Ed.,
"Path MTU Discovery for IP version 6", STD 87, RFC 8201,
DOI 10.17487/RFC8201, July 2017,
<https://www.rfc-editor.org/info/rfc8201>.
Appendix A. Example Of An Encapsulated IP Packet Flow
Below we show an example inner IP packet flow within the
encapsulating tunnel packet stream. Notice how encapsulated IP
Hopps Expires June 18, 2020 [Page 19]
Internet-Draft IP Traffic Flow Security December 2019
packets can start and end anywhere, and more than one or less than 1
may occur in a single encapsulating packet.
Offset: 0 Offset: 100 Offset: 2900 Offset: 1400
[ ESP1 (1500) ][ ESP2 (1500) ][ ESP3 (1500) ][ ESP4 (1500) ]
[--800--][--800--][60][-240-][--4000----------------------][pad]
Figure 3: Inner and Outer Packet Flow
The encapsulated IP packet flow (lengths include IP header and
payload) is as follows: an 800 octet packet, an 800 octet packet, a
60 octet packet, a 240 octet packet, a 4000 octet packet.
The "BlockOffset" values in the 4 IP-TFS payload headers for this
packet flow would thus be: 0, 100, 2900, 1400 respectively. The
first encapsulating packet ESP1 has a zero "BlockOffset" which points
at the IP data block immediately following the IP-TFS header. The
following packet ESP2s "BlockOffset" points inward 100 octets to the
start of the 60 octet data block. The third encapsulating packet
ESP3 contains the middle portion of the 4000 octet data block so the
offset points past its end and into the forth encapsulating packet.
The fourth packet ESP4s offset is 1400 pointing at the padding which
follows the completion of the continued 4000 octet packet.
Appendix B. A Send and Loss Event Rate Calculation
The current best practice indicates that congestion control should be
done in a TCP friendly way. A TCP friendly congestion control
algorithm is described in [RFC5348]. For our use case (as with
[RFC4342]) we consider our (fixed) packet size the segment size for
the algorithm. The formula for the send rate is then as follows:
1
X_Pps = -----------------------------------------------
R * (sqrt(2*p/3) + 12*sqrt(3*p/8)*p*(1+32*p^2))
Where "X_Pps" is the send rate in packets per second, "R" is the
round trip time estimate and "p" is the loss event rate (the inverse
of which is provided by the receiver).
The IP-TFS receiver, having the RTT estimate from the sender MAY use
the same method as described in [RFC4342] to collect the loss
intervals and calculate the loss event rate value using the weighted
average as indicated. The receiver communicates the inverse of this
value back to the sender in the IPTFS_PROTOCOL payload header field
"LossEventRate".
Hopps Expires June 18, 2020 [Page 20]
Internet-Draft IP Traffic Flow Security December 2019
The IP-TFS sender now has both the "R" and "p" values and can
calculate the correct sending rate ("X_Pps"). If following [RFC5348]
the sender SHOULD also use the slow start mechanism described therein
when the IP-TFS SA is first established.
Appendix C. Comparisons of IP-TFS
C.1. Comparing Overhead
C.1.1. IP-TFS Overhead
The overhead of IP-TFS is 40 bytes per outer packet. Therefore the
octet overhead per inner packet is 40 divided by the number of outer
packets required (fractional allowed). The overhead as a percentage
of inner packet size is a constant based on the Outer MTU size.
OH = 40 / Outer Payload Size / Inner Packet Size
OH % of Inner Packet Size = 100 * OH / Inner Packet Size
OH % of Inner Packet Size = 4000 / Outer Payload Size
Type IP-TFS IP-TFS IP-TFS
MTU 576 1500 9000
PSize 536 1460 8960
-------------------------------
40 7.46% 2.74% 0.45%
576 7.46% 2.74% 0.45%
1500 7.46% 2.74% 0.45%
9000 7.46% 2.74% 0.45%
Figure 4: IP-TFS Overhead as Percentage of Inner Packet Size
C.1.2. ESP with Padding Overhead
The overhead per inner packet for constant-send-rate padded ESP
(i.e., traditional IPsec TFC) is 36 octets plus any padding, unless
fragmentation is required.
When fragmentation of the inner packet is required to fit in the
outer IPsec packet, overhead is the number of outer packets required
to carry the fragmented inner packet times both the inner IP overhead
(20) and the outer packet overhead (36) minus the initial inner IP
overhead plus any required tail padding in the last encapsulation
packet. The required tail padding is the number of required packets
times the difference of the Outer Payload Size and the IP Overhead
minus the Inner Payload Size. So:
Hopps Expires June 18, 2020 [Page 21]
Internet-Draft IP Traffic Flow Security December 2019
Inner Paylaod Size = IP Packet Size - IP Overhead
Outer Payload Size = MTU - IPsec Overhead
Inner Payload Size
NF0 = ----------------------------------
Outer Payload Size - IP Overhead
NF = CEILING(NF0)
OH = NF * (IP Overhead + IPsec Overhead)
- IP Overhead
+ NF * (Outer Payload Size - IP Overhead)
- Inner Payload Size
OH = NF * (IPsec Overhead + Outer Payload Size)
- (IP Overhead + Inner Payload Size)
OH = NF * (IPsec Overhead + Outer Payload Size)
- Inner Packet Size
C.2. Overhead Comparison
The following tables collect the overhead values for some common L3
MTU sizes in order to compare them. The first table is the number of
octets of overhead for a given L3 MTU sized packet. The second table
is the percentage of overhead in the same MTU sized packet.
Type ESP+Pad ESP+Pad ESP+Pad IP-TFS IP-TFS IP-TFS
L3 MTU 576 1500 9000 576 1500 9000
PSize 540 1464 8964 536 1460 8960
-----------------------------------------------------------
40 500 1424 8924 3.0 1.1 0.2
128 412 1336 8836 9.6 3.5 0.6
256 284 1208 8708 19.1 7.0 1.1
536 4 928 8428 40.0 14.7 2.4
576 576 888 8388 43.0 15.8 2.6
1460 268 4 7504 109.0 40.0 6.5
1500 228 1500 7464 111.9 41.1 6.7
8960 1408 1540 4 668.7 245.5 40.0
9000 1368 1500 9000 671.6 246.6 40.2
Figure 5: Overhead comparison in octets
Hopps Expires June 18, 2020 [Page 22]
Internet-Draft IP Traffic Flow Security December 2019
Type ESP+Pad ESP+Pad ESP+Pad IP-TFS IP-TFS IP-TFS
MTU 576 1500 9000 576 1500 9000
PSize 540 1464 8964 536 1460 8960
-----------------------------------------------------------
40 1250.0% 3560.0% 22310.0% 7.46% 2.74% 0.45%
128 321.9% 1043.8% 6903.1% 7.46% 2.74% 0.45%
256 110.9% 471.9% 3401.6% 7.46% 2.74% 0.45%
536 0.7% 173.1% 1572.4% 7.46% 2.74% 0.45%
576 100.0% 154.2% 1456.2% 7.46% 2.74% 0.45%
1460 18.4% 0.3% 514.0% 7.46% 2.74% 0.45%
1500 15.2% 100.0% 497.6% 7.46% 2.74% 0.45%
8960 15.7% 17.2% 0.0% 7.46% 2.74% 0.45%
9000 15.2% 16.7% 100.0% 7.46% 2.74% 0.45%
Figure 6: Overhead as Percentage of Inner Packet Size
C.3. Comparing Available Bandwidth
Another way to compare the two solutions is to look at the amount of
available bandwidth each solution provides. The following sections
consider and compare the percentage of available bandwidth. For the
sake of providing a well understood baseline we will also include
normal (unencrypted) Ethernet as well as normal ESP values.
C.3.1. Ethernet
In order to calculate the available bandwidth we first calculate the
per packet overhead in bits. The total overhead of Ethernet is 14+4
octets of header and CRC plus and additional 20 octets of framing
(preamble, start, and inter-packet gap) for a total of 48 octets.
Additionally the minimum payload is 46 octets.
Size E + P E + P E + P IPTFS IPTFS IPTFS Enet ESP
MTU 590 1514 9014 590 1514 9014 any any
OH 74 74 74 78 78 78 38 74
------------------------------------------------------------
40 614 1538 9038 45 42 40 84 114
128 614 1538 9038 146 134 129 166 202
256 614 1538 9038 293 269 258 294 330
536 614 1538 9038 614 564 540 574 610
576 1228 1538 9038 659 606 581 614 650
1460 1842 1538 9038 1672 1538 1472 1498 1534
1500 1842 3076 9038 1718 1580 1513 1538 1574
8960 11052 10766 9038 10263 9438 9038 8998 9034
9000 11052 10766 18076 10309 9480 9078 9038 9074
Figure 7: L2 Octets Per Packet
Hopps Expires June 18, 2020 [Page 23]
Internet-Draft IP Traffic Flow Security December 2019
Size E + P E + P E + P IPTFS IPTFS IPTFS Enet ESP
MTU 590 1514 9014 590 1514 9014 any any
OH 74 74 74 78 78 78 38 74
--------------------------------------------------------------
40 2.0M 0.8M 0.1M 27.3M 29.7M 31.0M 14.9M 11.0M
128 2.0M 0.8M 0.1M 8.5M 9.3M 9.7M 7.5M 6.2M
256 2.0M 0.8M 0.1M 4.3M 4.6M 4.8M 4.3M 3.8M
536 2.0M 0.8M 0.1M 2.0M 2.2M 2.3M 2.2M 2.0M
576 1.0M 0.8M 0.1M 1.9M 2.1M 2.2M 2.0M 1.9M
1460 678K 812K 138K 747K 812K 848K 834K 814K
1500 678K 406K 138K 727K 791K 826K 812K 794K
8960 113K 116K 138K 121K 132K 138K 138K 138K
9000 113K 116K 69K 121K 131K 137K 138K 137K
Figure 8: Packets Per Second on 10G Ethernet
Size E + P E + P E + P IPTFS IPTFS IPTFS Enet ESP
590 1514 9014 590 1514 9014 any any
74 74 74 78 78 78 38 74
----------------------------------------------------------------------
40 6.51% 2.60% 0.44% 87.30% 94.93% 99.14% 47.62% 35.09%
128 20.85% 8.32% 1.42% 87.30% 94.93% 99.14% 77.11% 63.37%
256 41.69% 16.64% 2.83% 87.30% 94.93% 99.14% 87.07% 77.58%
536 87.30% 34.85% 5.93% 87.30% 94.93% 99.14% 93.38% 87.87%
576 46.91% 37.45% 6.37% 87.30% 94.93% 99.14% 93.81% 88.62%
1460 79.26% 94.93% 16.15% 87.30% 94.93% 99.14% 97.46% 95.18%
1500 81.43% 48.76% 16.60% 87.30% 94.93% 99.14% 97.53% 95.30%
8960 81.07% 83.22% 99.14% 87.30% 94.93% 99.14% 99.58% 99.18%
9000 81.43% 83.60% 49.79% 87.30% 94.93% 99.14% 99.58% 99.18%
Figure 9: Percentage of Bandwidth on 10G Ethernet
A sometimes unexpected result of using IP-TFS (or any packet
aggregating tunnel) is that, for small to medium sized packets, the
available bandwidth is actually greater than native Ethernet. This
is due to the reduction in Ethernet framing overhead. This increased
bandwidth is paid for with an increase in latency. This latency is
the time to send the unrelated octets in the outer tunnel frame. The
following table illustrates the latency for some common values on a
10G Ethernet link. The table also includes latency introduced by
padding if using ESP with padding.
Hopps Expires June 18, 2020 [Page 24]
Internet-Draft IP Traffic Flow Security December 2019
ESP+Pad ESP+Pad IP-TFS IP-TFS
1500 9000 1500 9000
------------------------------------------
40 1.14 us 7.14 us 1.17 us 7.17 us
128 1.07 us 7.07 us 1.10 us 7.10 us
256 0.97 us 6.97 us 1.00 us 7.00 us
536 0.74 us 6.74 us 0.77 us 6.77 us
576 0.71 us 6.71 us 0.74 us 6.74 us
1460 0.00 us 6.00 us 0.04 us 6.04 us
1500 1.20 us 5.97 us 0.00 us 6.00 us
Figure 10: Added Latency
Notice that the latency values are very similar between the two
solutions; however, whereas IP-TFS provides for constant high
bandwidth, in some cases even exceeding native Ethernet, ESP with
padding often greatly reduces available bandwidth.
Appendix D. Acknowledgements
We would like to thank Don Fedyk for help in reviewing this work.
Appendix E. Contributors
The following people made significant contributions to this document.
Lou Berger
LabN Consulting, L.L.C.
Email: lberger@labn.net
Author's Address
Christian Hopps
LabN Consulting, L.L.C.
Email: chopps@chopps.org
Hopps Expires June 18, 2020 [Page 25]