AM-PM-Networking-Day.pdf

AM-PM: Alternate Marking

for Network Telemetry

Tal Mizrahi, Gidi Navon, Carmi Arad, Giuseppe Fioccola,

Background

What is network telemetry?

Performance

measurement

Delay

Packet loss

Queue status

…

Why do we need telemetry?

Detection

Failures

‘Elephant’

flows

Congestion /

Network Telemetry

Operations, Administration, Maintenance (OAM)

Network measurement / monitoring:

Control Message

This Talk is Based on…

RFC 8321

draft-mizrahi-ippm-multiplexed-alternate-marking (internet draft)

T. Mizrahi, C. Arad, G. Fioccola, M. Cociglio, M. Chen, L. Zheng, and G. Mirsky. “Compact Alternate Marking Methods for Passive Performance Monitoring”, draft-mizrahi-ippm-compact-alternate-marking, work in progress, IETF, 2018.

+ 2 papers

Old-School Passive Monitoring

Counters

Per port

Queue State

Latency

Per flow

Per queue

Carrier Network OAM

OAM Protocols

IETF ICMPv4

IEEE 802.1ag ITU-T Y.1731

IETF ICMPv6 IETF IPPM

IP OAM Higher Layers Layer 3 Layer 2 Layer 1 ITU-T Y.1711 MPLS OAM IEEE 802.3ah

MPLS / PWE3 OAM Ethernet OAM ITU-T G.8113.1 MPLS-TP OAM IETF MPLS-TP OAM IETF LSP-Ping MPLS OAM IETF PWE3 VCCV IETF_BFD

Active measurement / monitoring:

Control Message

Fate Sharing

Piggybacked Measurement

Measurement info is piggybacked onto data packets

Piggybacked Metadata – IOAM / INT

IOAM / INT Domain

Analytics Server

Switches push local

metadata into header:

delay, queue state, …

Telemetry

Info

IOAM

In situ OAM

INT

In-band Network Telemetry

AM-PM

: What Can We Do with ONE Bit Per Packet?

Measurement

Marking Bit

000 11111

00000 111

Marking Bit

00000001000000000

AM-PM:

Pulse

Marking – Delay Measurement

Analytics Server

Time Sent: March 8th, 16:02, 123400789 nsec (UTC) Time Received: March 8th, 16:02, 123500789 nsec (UTC) Network Delay: 100 μsec

Servers Servers

Checks when

packet sent

Checks when

AM-PM:

Pulse

Marking – Loss Measurement

Counter: 2100 Counter: 2000 Packets lost: 100

Servers Servers

Records counter value

Packets Sent: 10,000

Packets Lost: 500 Packets Received: 9,500

Servers Servers

AM-PM:

Alternate

Marking – Loss Measurement

Counts number of packets received Counts number

of packets sent

Consistent counting:

•

Export the counter of each color

when it is not in use.

...

Servers Servers

AM-PM:

Double

Marking

Pulse bit: Delay

Step bit:

Loss

AM-PM:

Multiplexed

Marking

Servers Servers

ONE

bit per packet

Accurate loss and

delay measurement!

AM-PM:

Hashed

Marking

Servers Servers

H(Pkt) = Hash of the packet header

If H(Pkt)=0



Pulse

Measurement within a specific domain

How do we get a spare bit in the header?

Measurement

Unused fields in the header:

-

Spare bit in the IP DSCP

-

Unused IP flag

Dedicated bit(s) in the header.

Ongoing AM-PM work in the IETF:

QUIC

MPLS

NSH

BIER

Geneve

Large Scale Deployment in Telecom Italia

•

Mobile backhaul network ~ 1000 eNodeBs.

•

AM-PM one bit (step-based) loss measurement.

•

Uses unused bit in DSCP.

AM-PM Evaluation using Marvell Prestera Switches

loss and delay



congestion is detected

Traffic Generator

Management Monitored data flow Background traffic

Switch 1

Software Implementation using P4

S

1

S

2

S

3

H

1

H

2

Server

•

Technion undergraduate project.

•

Implemented in P4.

•

Tested in Mininet.

Time.Sec

1

Time.Frac

*

*

*

*

Periodic range

...

time

1 second

Time

field2 field3 field4 …

TCAM Switch

header / metadata

Implementing Multiplexed Marking:

Time-multiplexed Parsing

•

TimeFlip is used to divide time into time slots.

•

Time

0

1

000 001 010 011 100 101 110 111

IOAM / INT Domain

Analytics Server

Combining IOAM/INT with AM-PM

AM-PM

Pulse

as a trigger for

exporting telemetry info.

Per-hop Telemetry

Challenge

: export telemetry info without

the expensive overhead of IOAM/INT.

Network Telemetry: An Evolution

Ping

Traceroute

Passive

Monitoring

Carrier

OAM

References

[1] Fioccola, G., Capello, A., Cociglio, M., Castaldelli, L., Chen, M., Zheng, L., Mirsky, G., and T. Mizrahi, “Alternate Marking method for passive and hybrid performance monitoring”, RFC 8321, 2018.

[2] Mizrahi, T., Arad, C., Fioccola, G., Cociglio, M., Chen, M., Zheng, L., and G. Mirsky, “Compact Alternate Marking

Methods for Passive Performance Monitoring”, draft-mizrahi-ippm-compact-alternate-marking, work in progress, IETF, 2018.

[3] Brockners, F., Bhandari, S., Pignataro, C., Gredler, H., Leddy, J., Youell, S., Mizrahi, T., Mozes, D., Lapukhov, P., Chang, R. and D. Bernier, "Data Fields for In-situ OAM", draft-ietf-ippm-ioam-data-00, work in progress, 2017. [4] C. Kim et al., “In-band network telemetry (INT)”, P4 consortium, 2015.

[5] Mizrahi, T., Vovnoboy, V., Nisim, M., G. Navon, and A. Soffer, “Network Telemetry Solutions for Data Center and Enterprise Networks”, Marvell white paper, 2018.

[6] Mizrahi, T., Rottenstreich, O. and Y. Moses, “TimeFlip: Scheduling Network Updates with Timestamp-based TCAM Ranges”, IEEE INFOCOM, 2015.

[7] Mizrahi, T., Navon, G., Fioccola, G., Cociglio, M., Chen, M., and G. Mirsky, “AM-PM: Efficient Network Telemetry using Alternate Marking”, submitted, 2018.