Category: 标准

YANG Notification

 

Traditional approaches to remote network state visibility rely

heavily on polling. ?With polling, data is periodically explicitly

retrieved by a client from a server to stay up-to-date.

 

There are various issues associated with polling-based management:

 

o ?It introduces additional load on network, devices, and

applications. ?Each polling cycle requires a separate yet arguably

redundant request that results in an interrupt, requires parsing,

consumes bandwidth.

 

 

 

Clemm, et al. ? ? ? ? ? Expires December 17, 2016 ? ? ? ? ? ? ? [Page 3]

 

Internet-Draft ? ? ? ? ? ? ? ? ?YANG-Push ? ? ? ? ? ? ? ? ? ? ?June 2016

 

 

o ?It lacks robustness. ?Polling cycles may be missed, requests may

be delayed or get lost, often particularly in cases when the

network is under stress and hence exactly when the need for the

data is the greatest.

 

o ?Data may be difficult to calibrate and compare. ?Polling requests

may undergo slight fluctuations, resulting in intervals of

different lengths which makes data hard to compare. ?Likewise,

pollers may have difficulty issuing requests that reach all

devices at the same time, resulting in offset polling intervals

which again make data hard to compare.

Yang

YANG [RFC6020] was originally designed for the Netconf protocol

[RFC6241], which originally put most emphasis on configuration.

However, YANG is not restricted to configuration data. ?YANG

datastores, i.e. datastores that contain data modeled according using

YANG, can contain configuration as well as operational data. ?It is

therefore reasonable to expect that data in YANG datastores will

increasingly be used to support applications that are not focused on

managing configurations but that are, for example, related to service

assurance.

 

Service assurance applications typically involve monitoring

operational state of networks and devices; of particular interest are

changes that this data undergoes over time. ?Likewise, there are

applications in which data and objects from one datastore need to be

made available both to applications in other systems and to remote

datastores [I-D.voit-netmod-yang-mount-requirements]

[I-D.clemm-netmod-mount]. ?This requires mechanisms that allow remote

systems to become quickly aware of any updates to allow to validate

and maintain cross-network integrity and consistency.

 

Traditional approaches to remote network state visibility rely

heavily on polling. ?With polling, data is periodically explicitly

retrieved by a client from a server to stay up-to-date.