LOAD BALANCING WITH SDN/NFV

Transcription

1 LOAD BALANCING WITH SDN/NFV Gert Grammel CTO OFFICE

2 PROBLEM STATEMENT. Quality of Experience over a shared medium relies on flow identification and control. Applications have a limited capability to deal with packet reordering of a flow. Flows are not necessarily long lived 4. Data Centers are source&sink of zillions of flows 5. Infrastructure has to be built and operated to deal effectively with imbalances 6. SDN/NFV applications need to care about traffic patterns

3 STATE OF THE ART APPLICATIONS A flow is basically a sequence of packets between two applications Applications rely on the Internet to deliver the packets in sequence Protection against packet mis-ordering introduces additional delay 5 odd R S even odd R S even 4 6

4 STATE OF THE ART RECEIVER SIDE Is packet #n lost or delayed? How long to wait for #n after #n+ did arrive? TCP/IP throughput is delay and loss sensitive RTP is jitter, delay and loss sensitive 4 Conclusion: Since packet re-ordering in the current Internet is rare, many applications simply drop misordered packets, thereby reducing buffering&delay for a flow TCP throughput: 0/issue-6/features/cloud-services-hinge-on-application-performance-onwans.html

5 HOW CAN THE DC AND THE NETWORK AVOID PACKET RE-ORDERING? Switching equipment needs to identify flows and route all packets of those flows on the same facility (queues and links) 4 5 Flow-Y S Flow-X 4 But how to identify flows? 5

6 HOW TO DEAL WITH FLOWS IN DATA CENTERS? S S S S Internet R L L L L L L L L L L L L L L R Internet LOAD BALANCING NETWORK ADRESSING DPI/TDF VPN WEB AWARENESS Router LOAD BALANCING FIREWALL PARENTAL CONTROL APPLICATION CACHING & CONTENT 6

7 STORAGE LOAD BALANCING () WAN Internet Is this a good flow distribution? Is this still a good flow distribution? About Flows Router needs to look deep in the packet to identify flows Router does not know how big a flow will be Router does not know how long a flow will live Router does not know what other routers decide But this is a bad idea This looks good 7

8 VIDEO LOAD BALANCING () Is this still a good flow distribution? But this is a bad idea WAN Internet Is this a good flow distribution? About Flows Router needs to look deep in the packet to identify flows Router does not know how big a flow will be Router does not know how long a flow will live Router does not know what other routers decide This looks good 8

9 OTHER ISSUES IN IDENTIFYING FLOWS: TUNNELING One or two flows? How many bytes need to be inspected to decide? S Encaps Flow-Z 9

10 HOW ABOUT RINA? RINA has a strong hierarchy concept: Recursive encapsulation creates big flows Nodes are not allowed to look beyond the bottom layer in search for finer flows. If big flows are transported over smaller interfaces (e.g.lag) they must be split-up either introduce reassembly buffers and dimension them carefully Or find a way to identify (n-x)-dif PDU flows in a (n)-dif PDU flow -DIF a b c -DIF -DIF 0-DIF-a 0-DIF-b 0-DIF-c 0-DIF-d System System System System System 0

11 SDN USE CASE TRAFFIC DISTRIBUTION The goal of TD is to spread load across a few Paths such that the load on each Path is roughly the same and is within given bounds NE: Normalization Event (macro-adjustments) NE NS NS: Normalization Sampling (aggregate bandwidth samples) ABA ABA: Auto-bandwidth adjustment (micro-adjustments) timeline Usable BW samples At Normalization Event: Traffic is re-balanced based on flow information, route information and bandwidth 5% BW 95%

12 FUTURE: NFV SCHEDULER INCLUDING HOSTS Arbiter / Scheduler allocates time-slots and paths based on destination and size of the packets. Fastpass Datacenter Network, SIGCOMM 4, August 7-,04, Chciago, IL, USA CONTENT EU 7th Framework Programme 854

13 SUMMARY LOAD BALANCING SOLVES ACTUAL NETWORK PROBLEMS SIMPLIFIED OPERATIONS For operator and controller Same operational procedures whether integration is actual or virtual MIGRATION TO CONTROLLER- BASED NETWORK Allows two or more heterogeneous network elements to be managed as a single virtual network element Controller function may be separate or embedded in one of the network elements CREATES ECOSYSTEM where best-inclass products are designed to work together as a virtual unit From different product categories (routers, switches) From different layers (packet and optical) With different capability in scale and feature

14 THANK YOU 4