GCC (General Communication Channel ) bytes in OTN

General Communication Channel (GCC) bytes for overhead communication between network nodes.

•  The GCC is used for OAM functions such as performance monitoring, fault detection, and signaling and maintenance commands in support of protection switching, fault sectionalization, service-level reporting, and control plane communications
• GCC0 – two bytes within OTUk overhead. GCC0 is terminated at every 3R (re-shaping, re-timing, re-amplification) point and used to carry GMPLS signaling protocol and/or management information.
• GCC1/2 – four bytes (each of two bytes) within ODUk overhead. These bytes are used for client end-to-end information and shouldn't be touched by the OTN equipment.
• SONET/SDH where the data communication channel (DCC) has a constant data rate, GCC data rate depends on the OTN line rate. For example, GCC0 data rate in the case of OTU1 is ~333kbit/s, and for OTU2 its data rate is ~1.3 Mbit/s.

Practical scenario of monitoring GCC bytes :   

Service is created as OTU2 in Core network & metro network. 

GCC0 – two bytes within OTUk overhead for management information with respect remote management of NE ( Here it is Metro/Longhaul Network Equipment management)

Would like to get access of metro network by GGC0 byte enabling in metro & GCC0 transparent mode in core network.

Scenario is as below:-

Metro/Longhaul Network Equipment <---------------> Multiple Core Network Equipment’s ( 3rd Party Provider network) <---------------------> Metro/Longhaul Network Equipment

Alien wavelength

In the context of wavelength-division multiplexing, an alien wavelength is a "colored" optical signal that is originated from equipment not under the direct control of the transmission network operator. This technique was first mentioned in 2009.^[1]

Alien Wave transport involves transparent transmission of colored optical channels over preexisting third-party physical infrastructure. In other words, Alien Wave transport implies an innovative spectrum utilization arrangement between an optical infrastructure owner and a bandwidth crippled customer. The fact that multiple providers co-exist and utilize the common fiber and optical layer infrastructure turns out to be a viable and cost-effective way to scale-up network capacity through minimal capital and operational investments. A practical example of an Alien Wave implementation is one where network resources owned by one carrier are being utilized to transport optical channels that are in the control of a secondary carrier. The possibility of Alien Wave insertion without any impact to existing services has resulted in a rapid acceptance of this technology by the telecom service provider community.

Alien wavelengths enable to drive more capacity over any existing OTN/DWDM network infrastructure./p>

The increasing use and development of technologies such as 5G and automation, and growing consumption of the Internet of Things (IoT), 4K and video content have all lead to high demand for bandwidth. This poses a challenge for carriers, service providers, DCI and enterprises with scaling their existing WDM network infrastructure to meet the required transport capacity. While it is possible to plan for a sudden surge in requirement for bandwidth, it also may occur without warning, as different segments in the network may expand unpredictably and with it the need to support growing capacity and client interface speeds.

Alien wavelengths is the solution for this challenge, as it enables to drives capacity over any existing OTN/DWDM network without replacing infrastructure, and it is vendor-agnostic to third party Ethernet and Fibre Channel switch

The five must-haves of Alien Wavelengths: High Capacity, Scalable, Secured, Cost-effective, Fast Deployment

Concept of WSON

 Concept of WSON:-

 Objectives:-

       During this course we are going to focus on:

Ø An introduction to WSON technology

Ø A description of the WSON Control Plane

Ø A description of the WSON Protections

On completion of this course the participants will be able to:

Ø Describe what WSON is and which its main characteristics are.

Ø Differentiate between ASON and WSON

Ø Understand how WSON works and the relevant characteristics in terms of control plane and protection schemes introduced into the WDM layer

 Introduction of WSON:-

ASON, ASTN, WSON, GMPLS, as if all these technologies were the same, it seems to be useful to clarify some points about the terminology.

The acronym GMPLS that stands for Generalized Multi-Protocol Label Switching refers to a suite of protocols developed by IETF to extend the MPLS ideas outside the context of the IP world.

The acronym ASON that stands for Automatic Switched Optical Network is Recommendation developed by ITU-T that specifies the requirement to apply the GMPLS technology to a generic optical network; in this context, with the term “generic optical network” we refer both to an SDH or WDM network, or even to OTN (ODU switching) an MPLS-TP packet network.

In the SDH domain, the specific used acronym is ASTN that stands for Automatic Switched Transport Network and, also in this case, it is a recommendation developed by ITU-T. It’s a framework that represents the ITU-T ideas about how the GMPLS technology should be applied to the SDH world (fast rerouting of Virtual Containers).

Why do we need WSON?

What are the main advantages of the WSON network compared with a traditional network?

Ø There are three main advantages:

The most important advantage is that, in WSON, new protection schemas allow advanced network resilience mechanisms that can react, in an automatic way, also in case of multiple failures.

Ø The second advantage is the possibility for WSON to realize the automatic circuit

Provisioning: as a strategic point of evolution, WSON will be able, in the future, to provide circuits on demand, allowing an IP router, for example, to

Ask for a circuit directly to the WDM node that is at the ingress of the WSON, without passing through the NMS and the human operator.

Ø The third advantage is the strategic cost reduction mainly due to the fact that it is possible to share the protection bandwidth among a group of WSON circuits

AUTOMATICALLY SWITCHED OPTICAL NETWORK (ASON)

  AUTOMATICALLY SWITCHED OPTICAL NETWORK (ASON)

Before going to WSON, let’s have a brief look on ASON.

An Automatically Switched Optical Network (ASON) is an "intelligent" optical network that can automatically manage the signalling and routing through the network. Traditionally, it was necessary to configure cross-connections in the Network Elements (such as an optical switch) to create a new traffic path for a customer.

In an ASON, this process can be automated. The customer defines a new path by its start and end point, the bandwidth needed, the Quality of Service and so on. The Network Elements have the necessary processing functions built in to configure the new traffic path. The path itself is not specified by the customer. The ASON network creates a light path through the network for this customer. This traffic path will be changed if the network is changed.

There are three major protocols used in ASON

OSPF (To calculate the shortest path) >> Routing Protocol

RSVP (To reserve the resources and path) >> Signaling Protocol

LMP (Link Verification )>> To check Data and TE link

1. It will automatically select the shortest path in ROADM network
2.  It will help to  reserve the bandwidth and resources
3.  It will Monitor the link failure and all
4.  SPC  >> Electrical >> Circuit Switching >> (Switching Occurs from Cross connection card in ODU0 time slot)
5.  GMPLS suite is formed by the GMPLS protocol itself, are followings
6. GOSPF-TE, GRSVP-TE, LMP & OIF-UNI (Where G stands for Generalized)

Electrical switching v/s Optical switching

Electrical switching v/s Optical switching

Electrical switching	Optical switching
Switching done by Cross connection Card	Switching done by manual create mesh network in Roadm(WSS)
Time slot switching done Time slot= ODU 0 =One label	Wavelength switching done One Wavelength =one label
ASON work	WSON Work
Label reserved for time slot	Label reserved for wavelength
Same time slot not require for switching	Same wavelength require for switching
No of Label reserve depend on traffic capacity	Traffic independent