Subject: [CCAMP] draft-ietf-ccamp-optical-impairment-topology-yang: new paragraph added to sub-section 2.5.2

From: Dieter Beller <[email-masked]>
Date: Tue, 15 Dec 2020 09:23:23 +0100

Hi all,

following my action item, I drafted an additional paragraph at the end 
of sub-section 2.5.2 (text in blue below).

We can discuss it during our meeting later today.

2.5.2. Organizational Modes Organizations like operator groups, industry 
fora, or equipment vendors can define organizational modes, which will 
allow these organizations to make use of advanced transceiver 
capabilities going beyond existing standardized application codes. Such 
an organizational mode is identified by the organization-identifier 
attribute defining the scope and an operational-mode that is meaningful 
within the scope of the organization. Hence, the two attributes must 
always be considered together. Two transceivers are inter-operable, if 
they have at least one (organization-identifier, operational-mode) pair 
in common and if the supported carrier frequency and power attributes 
have a matching range. This is a necessary condition for path 
computation in the context of organizational modes. An operational mode 
is a transceiver preset (a configuration with well-defined parameter 
values) subsuming several transceiver properties including: o FEC type o 
Modulation scheme o Encoding (mapping of bit patterns (code words) to 
symbols in the constellation diagram) o Baud rate (symbol rate) o 
Carrier bandwidth (typically measured in GHz) The major reason for these 
transceiver presets is the fact that the attribute values typically 
cannot be configured independently and are therefore advertised as 
supported operational mode capabilities. It is the responsibility of the 
organization to assign operational modes and to ensure that operational 
modes are unique and not ambiguous within the scope of the organization. 
In addition to the transceiver properties subsumed by the operational 
mode, optical power and carrier frequency related properties are modeled 
separately, i.e., outside of the operational mode. This modeling 
approach allows transponders using different transceiver variants (e.g. 
optical modules) with slightly different power and/or frequency range 
properties to interoperate without defining separate operational modes. 
Different optical modules (pluggables) from different suppliers 
typically have slightly different input and output power ranges or may 
have slightly different carrier frequency tuning ranges. The received 
channel power and the received total power are two parameters that can 
be measured by the receiver and can be provided by the transceiver in 
order to allow a controller to determine the expected performance of the 
end-to-end service taking into account the optical impairments along the 
path. An organization may define the operational modes to include the 
optical power and carrier frequency related properties following the 
application code approach as defined in ITU-T Recommendation G.698.2 
[G.698.2]. In such a case, the explicit optical power and carrier 
frequency related optional attributes shall be omitted in order to avoid 
redundant information in the description of the transceiver 
capabilities. If these attributes are provided in addition to the 
operational modes including these attribute values implicitly, the 
parameter values provided explicitly replace the implicit values and 
take precedence. This shall, however, only be an done in exceptional 
cases and shall be avoided whenever possible. In summary, the optical 
power and carrier frequency related attributes shall either be described 
implicitly by the operational mode following the definition provided by 
that organization or shall be described explicitly when the optical 
power and carrier frequency related properties are not included in the 
operational mode definition.

Thanks,
Dieter