VeloCloud SD-WAN Business policy prioritization

Products

• VMware SD-WAN by VeloCloud

Issue/Introduction

Symptoms:
Training Documents

Environment

VMware SD-WAN by VeloCloud

Resolution

Business policy is an enhanced feature of Quality of Service in Velocloud. Business policy is setup only in outgoing direction and is used to increase or decrease the priority of a specific type of flow but is not used for dropping the packet. The VeloCloud examines the traffic being used, identifies the Application behavior, the business service objective required for a given app (High, Med, or Low), and the Edge WAN Link conditions, It optimizes Application behavior driving queuing, bandwidth utilization, link steering, and the mitigation of network errors.

A number of rules are predefined and you can add your own rules to customize your network operation.  Network traffic is managed by identifying its characteristics then matching the characteristics to the rule with the highest precedence. Setting up business policy for an Application which is not a routable APP, DPI will use the first few packets to identify the exact application and hence next flow will take effect with correct Biz policy. It won't be applied until the flows age out. So, flushing the flows from Test and Troubleshoot will apply the business policy changes immediately.

Biz Policy Configuration:

1. Network Service:

a. Direct: Edge will send out the packet directly to internet, no VCG is involved in exchange of packets

b. Multipath: This will load balance the traffic across multiple available WAN links

c. Cloud Proxy: If you choose the Cloud Proxy option, select a Cloud Proxy that you have pre-configured under Network Services or configure a new Cloud Proxy.

d. Internet Backhaul: Traffic from Spoke edges will come to the Hub (Backhaul) edge and Backhaul edge will route it to the internet. In prior releases, Internet Backhaul can only be done for routable apps, in Effen, Internet Backhaul can be done for all Applications and not limited to routable apps. Internet backhaul is also supported in Non-Velocloud site.

 

2. Link Steering:

- Transport Group

- Interface (Internet1 to 3 or USB 1 to 4)

- WAN link (Based upon service provider)

 

Transport Group: Provides WAN link binding on similar characteristics and functionality. Allows similar type of traffic to be pushed to similar links. Has following options:

- All

- Public Wired

- Public Wireless

- Private Wireless

 

Sub configuration options:

- Mandatory (Use only this link)

- Preferred (Use this link when SLA is met)

- Available (Use this link if it is Up)

Mandatory: when specified this indicates the traffic should mandatorily pick the WAN link or link Service-group specified. If the link specified(or all links within chosen service group) is not plugged in OR if multi-path gateway route chosen and path is DEAD, the corresponding pkt will be dropped.

Preferred: when specified this indicates the traffic should preferably pick the WAN link or link Service-group specified. If the link specified(or all links within chosen service group) is not plugged in OR if multi-path gateway route chosen and path is UNSTABLE OR link SLO is not met, the corresponding pkt will be steered on the next best available link. If the preferred link gets available again, traffic should be steered back on the preferred link.

Available: when specified this indicates the traffic should preferably pick the WAN link or link Service-group specified as long as it is available(irrespective of link SLO). If the link specified(or all links within chosen service group) is not plugged in OR if multi-path gateway route chosen and path is DEAD, the corresponding pkt will be steered on the next best available link. If the preferred link gets available again, traffic should be steered back on the available link.

Service Class : The Service Class parameter can be set to Real-time (time sensitive traffic), Transactional, or Bulk. This option is only for custom application. VeloCloud Apps/Categories fall in one of these categories.

 

Error Correction Techniques:

1. Re-sequence: Packets get divided into smaller chunks and assigned unique sequence number. When the packet arrives at destination, a decision is made to either forward the packet (packet in sequence), drop the packet (seq number is old) or store the packet (sequence number is for future packet). For a packet which gets dropped, redelivery is requested from the Source (Selective repeat ARQ)

2. Replicate: Same packet sent on multiple links (packet duplicity) and if duplicate packet arrives at destination, duplicate copies are discarded.
3. Jitter buffer:  Jitter buffer is a temporary storage buffer used to capture incoming data packets. It is used in packet-based networks to ensure the continuity of audio streams by smoothing out packet arrival times during periods of network congestion.