Transcript Troubleshooting VoIP in Converged Networks

SDN for Communications
Making the Network and
Applications Smarter and
Adaptable
Terry Slattery
Principal Architect
NetCraftsmen
CCIE #1026
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Agenda
History of Traditional Networking
SDN and UC
Where Are We Now?
Future Directions and Summary
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Traditional Networking
• Complex configurations
– Low-level CLI commands
access-list extended QOS-LOW-LATENCY-DATA
– Non-intuitive interactions ipremark
Latency sensitive Data application traffic
permit tcp host 10.1.1.2 any any
– QoS example:
permit tcp host 10.1.1.4 any any
deny ip any any
…
class-map match-any OUT-LOW-LATENCY-DATA
description Low-Latency Data
match access-group QOS-LOW-LATENCY-DATA
match ip dscp af21
With QoS …
policy-map OUT-QUEUING-REMOTE1
description Outbound queuing and scheduling
class OUT-LOW-LATENCY-DATA
bandwidth percent 20
queue-limit 100
random-detect
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Traditional Networking
• Relatively static configuration
– Difficult to synchronize with
business needs
– Not responsive to applications
– Encodes policy
I-Net
UC Traffic
Bulk Traffic
• Forwarding based on destination address
– Drives equal cost multi-path topologies
– Complex policy routing configuration
to implement policy routing
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Remote Site
Traditional Networking
• Low network utilization – 30-40%
– Reserve bandwidth for traffic bursts
– Unable to manage traffic with sufficient
granularity
• Applications and the network don’t communicate
– Apps can’t ask the network for special service
– The network can’t inform apps of network changes
– App and network teams often don’t work well together
• Config changes cause 40-80% of network problems
– Network issues create 60-80% of QoE problems
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The Agility Mismatch
• Compute and storage are very agile
– VMs can be created and moved within
minutes
– Containers (packaged apps) activate
in seconds
• Network changes are slow
– Change control systems induce delays
– Manual processes
– Network staff is often reluctant to use
automation
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What About Orchestration?
• Orchestration improves agility
– Is it sufficient?
– How well has it worked so far?
• It doesn’t do many things
– No simplification; adds complexity on top of the network
– Doesn’t help with multi-tenancy designs
– No improvements to security
• Applications and network still don’t communicate!
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We Need Something Better
• Bidirectional communications between
applications and the network
• Faster configuration through automation
• Simplify configurations with powerful abstractions
• Better security (built-in and provable)
• New forwarding path selection mechanisms
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Agenda
Traditional Networking
SDN and UC
Where Are We Now?
Future Directions and Summary
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What is Software Defined Networking?
• A new form of networking
• Decouples control from
packet forwarding
• Software control of the
network
• Abstractions hide details
of the infrastructure layer
• Network and applications
communicate with each
other
Image: Open Networking Foundation
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The Advantages of SDN
• Applications and Network communicate
• Networks become more dynamic and agile
• Centralized control system makes better decisions
– Programming is easily done
across multiple devices
• Packet forwarding based on
more than destination address
– New path selection protocols
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Example: Endpoint Tracking and Security
Medical
Record
System
SDN
Controller
Second Floor
Third Floor
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Endpoint Tracking and Security
Medical
Record
System
SDN
Controller
SDN Controller
Detects Workstation
Second Floor
Third Floor
Workstation
on Wheels
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Endpoint Tracking and Security
Medical
Record
System
SDN
Controller
Virtual Net Instance Forwarding
Table Updates
Second Floor
Third Floor
Workstation
on Wheels
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Endpoint Tracking and Security
Medical
Record
System
SDN
Controller
SDN Controller
Detects Workstation’s
New Location
Second Floor
Third Floor
Workstation
on Wheels
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Endpoint Tracking and Security
Medical
Record
System
VNI Forwarding
Table Updates
SDN
Controller
Second Floor
Third Floor
Workstation
on Wheels
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Architecture of SDN for UC
• UC controller
talks with QoS
Service App
• QoS Service App
talks with the SDN
controller
• SDN controller creates
a virtual network for
the UC infrastructure
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Lync and SDN Integration
Fred
Call Initiated
Wanda
Lync tells SDN Controller
Media Traffic
SDN Controller Adds QoS Settings
Traffic Flows Are Properly Handled
Ringing…
Set QoS DSCP Rules
SDN
Controller
Lync
SDN API
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Call Start
QoE
Services
SDN Control
Server
Application-to-SDN Architecture
UC
Application 2
(E.g., Collaboration)
UC
Application 1
(E.g., Voice)
Application Network Service North-Bound Interface (NBI)
SDN Solution
QoE
Services
Controller
Dynamic QoS
Marking
Admission Control
Traffic Engineering
Path Selection
Traffic Engineering
CoS Optimization
Administrator
NBI Interface
Application
Policy
Network Controller North-Bound Interfaces
SDN Network
Controller
South-Bound
Interfaces (OpenFlow, etc)
Topology
Network
Element
Network
Element
Inventory
Network
Element
Path
Computation
Network
Element
Flow
Programming
Network
Element
Network
Element
Statistics
Network Policy
Network
Element
IMTC Paper: “Automating UC Quality of Experience Using SDN, v2.02”
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QoE Service Functions
QoE
Services
Controller
Dynamic QoS
Marking
Admission Control
Traffic Engineering
Path Selection
Traffic Engineering
CoS Optimization
Application
Policy
• Dynamic QoS
– Apply QoS classification and marking at call setup
• Call Admission Control
– Integrated across multiple applications
• Dynamic traffic engineering
– Optimum path selection and Class of Service selection
• Application policy control
– Central control of policy rules
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Dynamic QoS Classification and Marking
• UC controller identifies media traffic endpoints
– Based on 5-tuple: Src IP+port, Dst IP+port, UDP/TCP
• Works with encrypted media traffic (Lync & Skype)
• Handles multiple UC systems
– Lync + Polycom + Skype
Media Traffic
• Consistent QoS
UC Controller
SDN Controller
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Call Admission Control
Fred
Wanda
UC tells SDN Controller
SDN Controller Returns Error
UC controller can:
• Return “Fast Busy”
• Force the call to G.729 codec and
Call Originate…
retry
Fast Busy
or change
codec
UC
Controller
SDN API
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30Kbps
available
SDN
Controller
Failed: 30Kbps
Call Start
QoE
Services
Call Admission Control With SDN
• Policy: handling oversubscription
–
–
–
–
Deny the call – communicated back to the UC controller
Drop the traffic – but looks like a network failure
Mark down – to what class?
The UC controller makes room for the new call
• CAC across multiple UC systems
– Multi-vendor (Cisco and Avaya due to a merger or
acquisition)
– Multiple media sources (e.g., Lync + Polycom + Skype)
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Handling Network Failures
• UC controller can make smart decisions
– Change codecs
– Reallocate bandwidth
– Terminate calls (with message)
Fred
Wanda
• Actions based on policy
– Policy set by administrator
UC
Controller
SDN API
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SDN
Controller
Failed: 30Kbps
QoE
Services
Dynamic Traffic Engineering
• Dynamically select a media traffic path
– Based on media traffic type
– Driven by current network loading and characteristics
• Path selection protocols
– IS-IS or OSPF – shortest path
to the destination IP
Path 1
– Constraint-based SPF
– Segment routing – source routing
using MPLS tags
– An area of research & development,
ideally suited to SDN
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Path 2
Example Policies
• Flexible oversubscription handling
–
–
–
–
Allow more calls when other traffic is light
Deny call or mark down media traffic
Move traffic to alternate paths
Lower BW codecs on all calls
• Resolve priority conflicts
Media Traffic
UC Controller
– UC vs healthcare traffic
• Dynamic path selection
Policy Definition
– Segregate realtime traffic
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SDN Controller
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Hybrid SDN: Legacy Core
UC Controller
Data
Center
Core
R3
Branch
R2
R4
RB
TP-B
R1
SDN Controller
HQ
Legacy core devices
Static QoS configurations
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TP-HQ
27
SDN-enabled edge devices
Call Start
UC Controller
Data
Center
Core
R3
Branch
R2
UC-SDN
Dialog
R4
Best Effort
R1
SDN Controller
Call Initiation
HQ
TP-HQ
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RB
28
TP-B
Dynamic QoS
UC Controller
Data
Center
Core
R3
Branch
R2
R4
EF Best Effort
R1
SDN Controller
Push QoS
Policy
TP-B
RB
Egress: EF
Ingress: BE
Egress: EF
Ingress: BE
HQ
TP-HQ
– QoS trust policy is enforced at the edge, per session
– Policy is removed and BW reservation cleared when the
call terminates
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Agenda
Traditional Networking
SDN and UC
Where Are We Now?
Future Directions and Summary
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SD-WAN Products
• Traffic policies for multipath WAN
–
–
–
–
Smart WAN optimization for multiple paths
Selects the path appropriate for the traffic
Allows link bandwidth aggregation
Centralized policy definition system
LTE
LTE
HQ
Branch
Internet
MPLS
SD-WAN Controller
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API Maturity
• Most APIs are low-level
– Some emulate CLI-level functionality
– Higher-level abstractions are being developed
• Scope (tagging) and End-Point-Groups
• Abstract QoS definitions (hides details of classification/marking)
– Documentation is often “early development”
• API Interfaces are maturing
– Middleware is a valuable component (e.g., QoE Services)
– Use-cases are helping define required functionality
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Management and Troubleshooting
• Existing tools may not work with dynamic networks
– New sets of alerts
• Alert when the network can’t accept a flow
• Alert when the control system can’t talk with an element
– Show troubleshooting information
• Path and configuration, including QoS, firewall, and load balancer
• Which app requested the change
– Logging
• Record the time when changes were made
• API call tracing
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Device and Interface Tagging
• Group devices by function or role
Branch
– Automation aid
– Group configuration
– Facilitates policy scopes
• Example
– Core policy: efficient queuing
and forwarding
– Branch policy: dynamic classification,
marking, and queuing
Core
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10.10.30.2
Staff Education
• Learn policy definition tools – Cisco’s ACI
– Begin thinking at a higher-level
• Automation and scripting – Ansible, Chef, Python
– Stop using manual change methods
• Learn the language of applications and servers
– Integrate with the rest of IT
• New monitoring and troubleshooting tools
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Agenda
Traditional Networking
SDN and UC
REST API
Future Directions and Summary
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Current State of SDN
• BigSwitch, Brocade, HP, and NEC are doing
OpenFlow switches and controllers
• Many vendors in the OpenDaylight consortium
– OpenFlow-based, open-source
• Cisco is doing several things
– OpenDaylight member
– Application Centric Infrastructure (proprietary)
• Monitoring Tool Networks (packet broker tools)
– BigSwitch (BigTap)
– NEC (PFTAP)
– Basic function of an SDN
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Current State of SDN
• Currently in the early adopter phase
– Many customers are interested in it (can it help me?)
– Look to successful full-scale deployments
– Many adopters benefit from operational efficiencies
• APIs are maturing
– API use will bring additional benefits
– Making it easier for apps to communicate with the
network
– Use-cases are helping define requirements
– Middleware will add new interfaces and capabilities
(QoE Service)
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Future Directions
• Network must communicate back to the application
– Communicate bandwidth changes (failure or new
capacity)
– Handling oversubscription
Healthcare Monitor
– Monitoring and diagnostics
Network
• Smart policy engines
UC Controller
– Help resolve conflicts
between applications
– Simplify policy creation
mechanisms
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SDN Controller
Policy Definitions
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Adopting SDN: Three Approaches
• Proof of concept
– Determine how SDN applies to your business
– Identify a justification (app, operational efficiencies, etc)
– Assemble an implementation team; learn the technology
• Cap and grow
– Cap existing infrastructure
– Install and grow SDN infrastructure,
linked to the legacy network
• Full Deployment (see vendor case studies)
– Complete replacement with SDN
– Fastest way to achieve the benefits of SDN
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SDN Migration
• Deploy the SDN-capable edge
–
–
–
–
SD-WAN and LAN edge switches
Where dynamic policies are applied
Use static policies in the core
Advantage: incremental deployment
• Upgrade the core
– Fast switches
– High bandwidth links
– Redundant connections
to the existing network
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Leaf-Spine core network design
Summary
Branch
• Need high level abstractions
10.10.30.2
– Simplify how we think about networks
– Device groups - use device tags
– Interface groups – interface tags or
End Point Groups (EPGs)
– Device-independent QoS definitions
– L3 forwarding domains (multi-tenancy)
• Prediction
– Today: One application per VM
– Future: One application per L3 network domain
Core
• Simplify service chaining
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Summary
• SDN is happening!
– Progress has been rapid
– Production rollout can be limited by equipment refresh
– Significant operational benefits can be realized
• Learning about SDN
– https://www.sdxcentral.com/
– http://www.netcraftsmen.com/resources/sdn-resources/
• It’s about the applications!
– Easier to deploy
– More agile
– Easier to manage
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Questions?
SDN for Communications
Making the Network and Applications
Smarter and Adaptable
Terry Slattery
Principal Consultant
NetCraftsmen
CCIE #1026
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Rights Reserved
44