THE CHANGING WAN
MATCHING THE WAN TO BUSINESS NEEDS
James Walker, Vice President Managed Network Services
WAN Summit 7th October 2015
tatacommunications.com |
@tata_comm
tatacommunications-newworld.com | youtube.com/user/tatacomms
© 2015 Tata Communications. All Rights Reserved. TATA COMMUNICATIONS and TATA are trademarks of Tata Sons Limited in certain countries.
So, what’s new?
•  The rise and rise of the cloud
•  Bringing challenges of :
•  Integration with legacy systems
•  Private vs public connectivity
•  Alignment with internal policies, security requirements, regulatory obligations
•  Barriers to entry for smaller cloud providers
•  Increasing use of hybrid VPNs
•  Cost reductions
•  More challenges :
•  Load balancing (MP BGP)
•  Asymmetric routing
•  Cloud connectivity
•  Full dual link utilisation
•  The arrival of early SDWAN services
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
2
Customer requirements
Network-centric
•
•
•
•
•
•
•
Extensive in-house network expertise
Complex traffic engineering requirements
Deterministic behaviour
High speed core, regional meet-me
Private network
Limited public cloud, little if any SaaS
Tendency to have significant on-premise
applications
•  Audit, compliance and security
requirements
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
Application-centric
•  Limited internal network expertise
•  Application performance critical
•  Hybrid networks, mix of private and public
traffic
•  Want to increase utilisation levels of the
network
•  Increasing use of public cloud and SaaS
Network requirements
Network-centric
•  Deterministic pathing
•  Minimise visibility of customer’s routing
table
•  Predictable network performance
•  Complex DR scenarios
•  Possible overlay networks
•  Generally high speed (1G+) and growing
•  Challenges around internal cost allocation
and logical separation
•  Dynamic bandwidth potentially required
•  Limited sites
•  Service multiplexing
•  “TEaaS”
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
Application-centric
•
•
•
•
•
•
•
•
•
Managed services
Application visibility and reporting
Performance optimisation
Intelligent load balancing, pathing and use
of network resources
Integration of multiple services (UC,
Internet)
Connectivity to public cloud
A network that dynamically reacts to
application performance and needs
Overlay network requirements
Typically multi-vendor, multi service
HYBRID VPNS
… AND SDWAN
tatacommunications.com |
@tata_comm
tatacommunications-newworld.com | youtube.com/user/tatacomms
© 2015 Tata Communications. All Rights Reserved. TATA COMMUNICATIONS and TATA are trademarks of Tata Sons Limited in certain countries.
Let’s start with something very basic
•
No contention in the core
•
SLA guarantees available
•
Premium link
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
•  Unpredictable with potential
contention and jitter
•  Best effort based
•  “Cheap and cheerful” link
A few more scene-setting thoughts
•  Last mile connectivity is the biggest cost in a network
•  Secondary circuit is hardly used (traffic flows less than
1% of the time)
VPN
•  Network managers are forced to manage congestion on
the primary circuit while the secondary circuit lies idle
•  Backup links fail and no-one notices until they’re needed
Network management best practice
•  For short term bursts – apply QOS techniques and don’t increase
bandwidth
•  Long term high link utilization – buy more bandwidth, burst or
offload traffic to alternate path
•  Frequent path change causes harm
•  Always route critical traffic on the best path
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
Primary Circuit
Secondary Circuit
Now, a little background on SDWAN
This is Cisco IWAN – but most SDWAN solutions have
similar concepts
•
•
•
•
•
Traffic is hub and spoke
Metrics are measured from the hub to the spokes
Path selection based on metrics
Path abstraction (in IWAN, using DMVPN technology)
Hub Master controller automatically pushes policy to
spokes
•  Multiple DCs are supported using a concept called a
transit site
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
SDWAN – still evolving
•  Questions customers should ask their SDWAN provider
•  Do all sites need two connections, or can I have single attached sites?
•  Do all sites have to participate in the overlay?
•  What about IaaS sites?
•  Do I have to migrate everything at once?
•  Can I control spoke to spoke traffic?
•  Can I have different traffic policies at different DCs?
•  When the primary fails at the DC, does all traffic fail over to the
alternate path (for hybrid sites, this is the Internet…)?
•  What is the impact on router throughput, are older/smaller routers
supported?
70-80% reduction
•  How do I handle local internet breakout at hybrid sites? ?
•  Will my load balancing policy cause any issues?
ü
û
û
û
ü
ü
û
ü
û
ü
Asymmetric routing
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
9
Problem statement
Metric based approach – Path Oscillation Problem
Link utilization
increases on
last mile
Premium
applications
are offloaded
again.
Congestion
reoccurs
Metric for
critical
application
(that has the
most stringent
requirements)
drops first
Variable
internet
performance
impacts
application
performance
metrics
Critical
applications
are offloaded
Offloading
causes
metrics to
improve
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
Final thoughts
•  New applications, cloud and the move to hybrid networking is a very fundamental change
•  Local internet breakout, connections to cloud (eg O365, Skype) and legacy applications are very
complex to manage efficiently
•  Managing application prioritisation and failover remains difficult
•  Service providers – and the industry – are in a state of flux
•  Enterprise customers sit on a spectrum with a spread of requirements which become very different at
the two ends
•  SDN and NFV are not yet here and continue to evolve
•  Customers have problems now
•  Overlay providers are an attractive option for frustrated enterprises
•  … but can introduce rafts of new issues, and not fix the old ones
•  There is no silver bullet
•  Back to the future?
•  While supporting SDWAN, we are also investing heavily in innovation using “legacy” protocols
•  Visibility, efficiency, predictability and control are the objectives
www.tatacommunications.com | @tata_comm
http://tatacommunications-newworld.com | www.youtube.com/user/tatacomms
© 2012 Tata Communications Ltd. All rights reserved. TATA COMMUNICATIONS and
TATA are trademarks of Tata Sons Limited in certain countries.
11
THANK YOU
tatacommunications.com |
@tata_comm
tatacommunications-newworld.com | youtube.com/user/tatacomms
© 2015 Tata Communications. All Rights Reserved. TATA COMMUNICATIONS and TATA are trademarks of Tata Sons Limited in certain countries.