From fef9d88a38e010813c322c0eab4e852b05867f60 Mon Sep 17 00:00:00 2001 From: "Bozawglanian, Hagop (hb755d)" Date: Thu, 19 Jul 2018 21:28:26 +0000 Subject: VNFRQTS - Updating requirements to new structure Updating the requirements to use the newly developed RST directive Removing Chapter 7 updates to see if build would work. Change-Id: I43bffa2b6c0a15e6f2e179c00d39f4ee46c5a046 Issue-ID: VNFRQTS-245 Signed-off-by: Bozawglanian, Hagop (hb755d) --- .../VNF-On-boarding-and-package-management.rst | 708 +++++++++++++++------ 1 file changed, 516 insertions(+), 192 deletions(-) (limited to 'docs/Chapter7/VNF-On-boarding-and-package-management.rst') diff --git a/docs/Chapter7/VNF-On-boarding-and-package-management.rst b/docs/Chapter7/VNF-On-boarding-and-package-management.rst index 7628aaa..226efd6 100644 --- a/docs/Chapter7/VNF-On-boarding-and-package-management.rst +++ b/docs/Chapter7/VNF-On-boarding-and-package-management.rst @@ -27,232 +27,557 @@ and GS NFV IFA011 V0.3.0 (2015-10) - Network Functions Virtualization Resource Description ^^^^^^^^^^^^^^^^^^^^^^ -* R-77707 The xNF provider **MUST** include a Manifest File that - contains a list of all the components in the xNF package. -* R-66070 The xNF Package **MUST** include xNF Identification Data to - uniquely identify the resource for a given xNF provider. The identification - data must include: an identifier for the xNF, the name of the xNF as was - given by the xNF provider, xNF description, xNF provider, and version. -* R-69565 The xNF Package **MUST** include documentation describing xNF - Management APIs, which must include information and tools for ONAP to - deploy and configure (initially and ongoing) the xNF application(s) - (e.g., NETCONF APIs) which includes a description of configurable - parameters for the xNF and whether the parameters can be configured - after xNF instantiation. -* R-00156 The xNF Package **MUST** include documentation describing xNF - Management APIs, which must include information and tools for ONAP - to monitor the health of the xNF (conditions that require healing - and/or scaling responses). -* R-00068 The xNF Package **MUST** include documentation which includes - a description of parameters that can be monitored for the xNF and - event records (status, fault, flow, session, call, control plane, - etc.) generated by the xNF after instantiation. -* R-12678 The xNF Package **MUST** include documentation which includes a - description of runtime lifecycle events and related actions (e.g., - control responses, tests) which can be performed for the xNF. -* R-84366 The xNF Package **MUST** include documentation describing - xNF Functional APIs that are utilized to build network and - application services. This document describes the externally exposed - functional inputs and outputs for the xNF, including interface - format and protocols supported. -* R-36280 The xNF provider **MUST** provide documentation describing - xNF Functional Capabilities that are utilized to operationalize the - xNF and compose complex services. -* R-98617 The xNF provider **MUST** provide information regarding any - dependency (e.g., affinity, anti-affinity) with other xNFs and resources. + +.. req:: + :id: R-77707 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** include a Manifest File that + contains a list of all the components in the xNF package. + +.. req:: + :id: R-66070 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include xNF Identification Data to + uniquely identify the resource for a given xNF provider. The identification + data must include: an identifier for the xNF, the name of the xNF as was + given by the xNF provider, xNF description, xNF provider, and version. + +.. req:: + :id: R-69565 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing xNF + Management APIs, which must include information and tools for ONAP to + deploy and configure (initially and ongoing) the xNF application(s) + (e.g., NETCONF APIs) which includes a description of configurable + parameters for the xNF and whether the parameters can be configured + after xNF instantiation. + +.. req:: + :id: R-00156 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing xNF + Management APIs, which must include information and tools for + ONAP to monitor the health of the xNF (conditions that require + healing and/or scaling responses). + +.. req:: + :id: R-00068 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation which includes + a description of parameters that can be monitored for the xNF + and event records (status, fault, flow, session, call, control + plane, etc.) generated by the xNF after instantiation. + +.. req:: + :id: R-12678 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation which includes a + description of runtime lifecycle events and related actions (e.g., + control responses, tests) which can be performed for the xNF. + +.. req:: + :id: R-84366 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing + xNF Functional APIs that are utilized to build network and + application services. This document describes the externally exposed + functional inputs and outputs for the xNF, including interface + format and protocols supported. + +.. req:: + :id: R-36280 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide documentation describing + xNF Functional Capabilities that are utilized to operationalize the + xNF and compose complex services. + +.. req:: + :id: R-98617 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide information regarding any + dependency (e.g., affinity, anti-affinity) with other xNFs and resources. Resource Configuration ^^^^^^^^^^^^^^^^^^^^^^^ -* R-89571 The xNF **MUST** support and provide artifacts for configuration - management using at least one of the following technologies; - a) Netconf/YANG, b) Chef, or c) Ansible. - Note: The requirements for Netconf/YANG, Chef, and Ansible protocols - are provided separately and must be supported only if the corresponding - protocol option is provided by the xNF providor. +.. req:: + :id: R-89571 + :target: XNF + :keyword: MUST + + The xNF **MUST** support and provide artifacts for configuration + management using at least one of the following technologies; + a) Netconf/YANG, b) Chef, or c) Ansible. + + Note: The requirements for Netconf/YANG, Chef, and Ansible protocols + are provided separately and must be supported only if the corresponding + protocol option is provided by the xNF providor. + Configuration Management via NETCONF/YANG ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -* R-30278 The xNF provider **MUST** provide a Resource/Device YANG model - as a foundation for creating the YANG model for configuration. This will - include xNF attributes/parameters and valid values/attributes configurable - by policy. +.. req:: + :id: R-30278 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide a Resource/Device YANG model + as a foundation for creating the YANG model for configuration. This will + include xNF attributes/parameters and valid values/attributes configurable + by policy. Configuration Management via Chef ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -* R-13390 The xNF provider **MUST** provide cookbooks to be loaded - on the appropriate Chef Server. -* R-18525 The xNF provider **MUST** provide a JSON file for each - supported action for the xNF. The JSON file must contain key value - pairs with all relevant values populated with sample data that illustrates - its usage. The fields and their description are defined in Tables A1 - and A2 in the Appendix. - Note: Chef support in ONAP is not currently available and planned for 4Q 2017. +.. req:: + :id: R-13390 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide cookbooks to be loaded + on the appropriate Chef Server. + +.. req:: + :id: R-18525 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide a JSON file for each + supported action for the xNF. The JSON file must contain key value + pairs with all relevant values populated with sample data that illustrates + its usage. The fields and their description are defined in Tables A1 + and A2 in the Appendix. + + Note: Chef support in ONAP is not currently available and planned for 4Q 2017. + Configuration Management via Ansible ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -* R-75608 The xNF provider **MUST** provide playbooks to be loaded - on the appropriate Ansible Server. -* R-16777 The xNF provider **MUST** provide a JSON file for each - supported action for the xNF. The JSON file must contain key value - pairs with all relevant values populated with sample data that illustrates - its usage. The fields and their description are defined in Table B1 - in the Appendix. - -* R-46567 The xNF Package **MUST** include configuration scripts - for boot sequence and configuration. -* R-16065 The xNF provider **MUST** provide configurable parameters - (if unable to conform to YANG model) including xNF attributes/parameters - and valid values, dynamic attributes and cross parameter dependencies - (e.g., customer provisioning data). + +.. req:: + :id: R-75608 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide playbooks to be loaded + on the appropriate Ansible Server. + +.. req:: + :id: R-16777 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide a JSON file for each + supported action for the xNF. The JSON file must contain key value + pairs with all relevant values populated with sample data that illustrates + its usage. The fields and their description are defined in Table B1 + in the Appendix. + +.. req:: + :id: R-46567 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include configuration scripts + for boot sequence and configuration. + +.. req:: + :id: R-16065 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide configurable parameters + (if unable to conform to YANG model) including xNF attributes/parameters + and valid values, dynamic attributes and cross parameter dependencies + (e.g., customer provisioning data). Resource Control Loop ^^^^^^^^^^^^^^^^^^^^^^^ -* R-22888 The xNF provider **MUST** provide documentation for the xNF - Policy Description to manage the xNF runtime lifecycle. The document - must include a description of how the policies (conditions and actions) - are implemented in the xNF. -* R-01556 The xNF Package **MUST** include documentation describing the - fault, performance, capacity events/alarms and other event records - that are made available by the xNF. -* R-16875 The xNF Package **MUST** include documentation which must include - a unique identification string for the specific xNF, a description of - the problem that caused the error, and steps or procedures to perform - Root Cause Analysis and resolve the issue. -* R-35960 The xNF Package **MUST** include documentation which must include - all events, severity level (e.g., informational, warning, error) and - descriptions including causes/fixes if applicable for the event. -* R-42018 The xNF Package **MUST** include documentation which must include - all events (fault, measurement for xNF Scaling, Syslogs, State Change - and Mobile Flow), that need to be collected at each VM, VNFC (defined in `VNF Guidelines `__ ) and for the overall xNF. -* R-27711 The xNF provider **MUST** provide an XML file that contains a - list of xNF error codes, descriptions of the error, and possible - causes/corrective action. -* R-01478 The xNF Package **MUST** include documentation describing all - parameters that are available to monitor the xNF after instantiation - (includes all counters, OIDs, PM data, KPIs, etc.) that must be - collected for reporting purposes. -* R-73560 The xNF Package **MUST** include documentation about monitoring - parameters/counters exposed for virtual resource management and xNF - application management. -* R-90632 The xNF Package **MUST** include documentation about KPIs and - metrics that need to be collected at each VM for capacity planning - and performance management purposes. -* R-86235 The xNF Package **MUST** include documentation about the monitoring - parameters that must include latencies, success rates, retry rates, load - and quality (e.g., DPM) for the key transactions/functions supported by - the xNF and those that must be exercised by the xNF in order to perform - its function. -* R-33904 The xNF Package **MUST** include documentation for each KPI, provide - lower and upper limits. -* R-53598 The xNF Package **MUST** include documentation to, when relevant, - provide a threshold crossing alert point for each KPI and describe the - significance of the threshold crossing. -* R-69877 The xNF Package **MUST** include documentation for each KPI, - identify the suggested actions that need to be performed when a - threshold crossing alert event is recorded. -* R-22680 The xNF Package **MUST** include documentation that describes - any requirements for the monitoring component of tools for Network - Cloud automation and management to provide these records to components - of the xNF. -* R-33694 The xNF Package **MUST** include documentation to when applicable, - provide calculators needed to convert raw data into appropriate reporting - artifacts. -* R-56815 The xNF Package **MUST** include documentation describing - supported xNF scaling capabilities and capacity limits (e.g., number - of users, bandwidth, throughput, concurrent calls). -* R-48596 The xNF Package **MUST** include documentation describing - the characteristics for the xNF reliability and high availability. -* R-74763 The xNF provider **MUST** provide an artifact per xNF that contains - all of the xNF Event Records supported. The artifact should include - reference to the specific release of the xNF Event Stream Common Event - Data Model document it is based on. (e.g., - `VES Event Listener `__) + +.. req:: + :id: R-22888 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide documentation for the xNF + Policy Description to manage the xNF runtime lifecycle. The document + must include a description of how the policies (conditions and actions) + are implemented in the xNF. + +.. req:: + :id: R-01556 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing the + fault, performance, capacity events/alarms and other event records + that are made available by the xNF. + +.. req:: + :id: R-16875 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation which must include + a unique identification string for the specific xNF, a description of + the problem that caused the error, and steps or procedures to perform + Root Cause Analysis and resolve the issue. + +.. req:: + :id: R-35960 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation which must include + all events, severity level (e.g., informational, warning, error) and + descriptions including causes/fixes if applicable for the event. + +.. req:: + :id: R-42018 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation which must include + all events (fault, measurement for xNF Scaling, Syslogs, State Change + and Mobile Flow), that need to be collected at each VM, VNFC (defined in `VNF Guidelines `__ ) and for the overall xNF. + +.. req:: + :id: R-27711 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide an XML file that contains a + list of xNF error codes, descriptions of the error, and possible + causes/corrective action. + +.. req:: + :id: R-01478 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing all + parameters that are available to monitor the xNF after instantiation + (includes all counters, OIDs, PM data, KPIs, etc.) that must be + collected for reporting purposes. + +.. req:: + :id: R-73560 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation about monitoring + parameters/counters exposed for virtual resource management and xNF + application management. + +.. req:: + :id: R-90632 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation about KPIs and + metrics that need to be collected at each VM for capacity planning + and performance management purposes. + +.. req:: + :id: R-86235 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation about the monitoring + parameters that must include latencies, success rates, retry rates, load + and quality (e.g., DPM) for the key transactions/functions supported by + the xNF and those that must be exercised by the xNF in order to perform + its function. + +.. req:: + :id: R-33904 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation for each KPI, provide + lower and upper limits. + +.. req:: + :id: R-53598 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation to, when relevant, + provide a threshold crossing alert point for each KPI and describe the + significance of the threshold crossing. + +.. req:: + :id: R-69877 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation for each KPI, + identify the suggested actions that need to be performed when a + threshold crossing alert event is recorded. + +.. req:: + :id: R-22680 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation that describes + any requirements for the monitoring component of tools for Network + Cloud automation and management to provide these records to components + of the xNF. + +.. req:: + :id: R-33694 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation to when applicable, + provide calculators needed to convert raw data into appropriate reporting + artifacts. + +.. req:: + :id: R-56815 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing + supported xNF scaling capabilities and capacity limits (e.g., number + of users, bandwidth, throughput, concurrent calls). + +.. req:: + :id: R-48596 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing + the characteristics for the xNF reliability and high availability. + +.. req:: + :id: R-74763 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide an artifact per xNF that contains + all of the xNF Event Records supported. The artifact should include + reference to the specific release of the xNF Event Stream Common Event + Data Model document it is based on. (e.g., + `VES Event Listener `__) Compute, Network, and Storage Requirements ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -* R-35851 The xNF Package **MUST** include xNF topology that describes - basic network and application connectivity internal and external to the - xNF including Link type, KPIs, Bandwidth, latency, jitter, QoS (if - applicable) for each interface. -* R-97102 The VNF Package **MUST** include VM requirements via a Heat - template that provides the necessary data for VM specifications - for all VNF components - for hypervisor, CPU, memory, storage. -* R-20204 The VNF Package **MUST** include VM requirements via a Heat - template that provides the necessary data for network connections, - interface connections, internal and external to VNF. -* R-44896 The VNF Package **MUST** include VM requirements via a Heat - template that provides the necessary data for high availability - redundancy model. -* R-55802 The VNF Package **MUST** include VM requirements via a Heat - template that provides the necessary data for scaling/growth VM - specifications. - - Note: Must comply with the *Heat requirements in 5.b*. - -* R-26881 The xNF provider **MUST** provide the binaries and images - needed to instantiate the xNF (xNF and VNFC images). -* R-96634 The xNF provider **MUST** describe scaling capabilities - to manage scaling characteristics of the xNF. +.. req:: + :id: R-35851 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include xNF topology that describes + basic network and application connectivity internal and external to the + xNF including Link type, KPIs, Bandwidth, latency, jitter, QoS (if + applicable) for each interface. + +.. req:: + :id: R-97102 + :target: VNF + :keyword: MUST + + The VNF Package **MUST** include VM requirements via a Heat + template that provides the necessary data for VM specifications + for all VNF components - for hypervisor, CPU, memory, storage. + +.. req:: + :id: R-20204 + :target: VNF + :keyword: MUST + + The VNF Package **MUST** include VM requirements via a Heat + template that provides the necessary data for network connections, + interface connections, internal and external to VNF. + +.. req:: + :id: R-44896 + :target: VNF + :keyword: MUST + + The VNF Package **MUST** include VM requirements via a Heat + template that provides the necessary data for high availability + redundancy model. + +.. req:: + :id: R-55802 + :target: VNF + :keyword: MUST + + The VNF Package **MUST** include VM requirements via a Heat + template that provides the necessary data for scaling/growth VM + specifications. + + Note: Must comply with the *Heat requirements in 5.b*. + +.. req:: + :id: R-26881 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide the binaries and images + needed to instantiate the xNF (xNF and VNFC images). + +.. req:: + :id: R-96634 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** describe scaling capabilities + to manage scaling characteristics of the xNF. Testing ^^^^^^^^^^ -* R-43958 The xNF Package **MUST** include documentation describing - the tests that were conducted by the xNF providor and the test results. -* R-04298 The xNF provider **MUST** provide their testing scripts to - support testing. -* R-58775 The xNF provider **MUST** provide software components that - can be packaged with/near the xNF, if needed, to simulate any functions - or systems that connect to the xNF system under test. This component is - necessary only if the existing testing environment does not have the - necessary simulators. + +.. req:: + :id: R-43958 + :target: XNF + :keyword: MUST + + The xNF Package **MUST** include documentation describing + the tests that were conducted by the xNF providor and the test results. + +.. req:: + :id: R-04298 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide their testing scripts to + support testing. + +.. req:: + :id: R-58775 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide software components that + can be packaged with/near the xNF, if needed, to simulate any functions + or systems that connect to the xNF system under test. This component is + necessary only if the existing testing environment does not have the + necessary simulators. Licensing Requirements ^^^^^^^^^^^^^^^^^^^^^^^ -* R-85653 The xNF **MUST** provide metrics (e.g., number of sessions, - number of subscribers, number of seats, etc.) to ONAP for tracking - every license. -* R-44125 The xNF provider **MUST** agree to the process that can - be met by Service Provider reporting infrastructure. The Contract - shall define the reporting process and the available reporting tools. -* R-40827 The xNF provider **MUST** enumerate all of the open - source licenses their xNF(s) incorporate. -* R-97293 The xNF provider **MUST NOT** require audits of - Service Provider’s business. -* R-44569 The xNF provider **MUST NOT** require additional - infrastructure such as a xNF provider license server for xNF provider - functions and metrics. -* R-13613 The VNF **MUST** provide clear measurements for licensing - purposes to allow automated scale up/down by the management system. -* R-27511 The VNF provider **MUST** provide the ability to scale - up a VNF provider supplied product during growth and scale down a - VNF provider supplied product during decline without “real-time” - restrictions based upon VNF provider permissions. -* R-85991 The xNF provider **MUST** provide a universal license key - per xNF to be used as needed by services (i.e., not tied to a VM - instance) as the recommended solution. The xNF provider may provide - pools of Unique xNF License Keys, where there is a unique key for - each xNF instance as an alternate solution. Licensing issues should - be resolved without interrupting in-service xNFs. -* R-47849 The xNF provider **MUST** support the metadata about - licenses (and their applicable entitlements) as defined in this - document for xNF software, and any license keys required to authorize - use of the xNF software. This metadata will be used to facilitate - onboarding the xNF into the ONAP environment and automating processes - for putting the licenses into use and managing the full lifecycle of - the licenses. The details of this license model are described in - Tables C1 to C8 in the Appendix. Note: License metadata support in - ONAP is not currently available and planned for 1Q 2018. + +.. req:: + :id: R-85653 + :target: XNF + :keyword: MUST + + The xNF **MUST** provide metrics (e.g., number of sessions, + number of subscribers, number of seats, etc.) to ONAP for tracking + every license. + +.. req:: + :id: R-44125 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** agree to the process that can + be met by Service Provider reporting infrastructure. The Contract + shall define the reporting process and the available reporting tools. + +.. req:: + :id: R-40827 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** enumerate all of the open + source licenses their xNF(s) incorporate. + +.. req:: + :id: R-97293 + :target: XNF + :keyword: MUST NOT + + The xNF provider **MUST NOT** require audits + of Service Provider's business. + +.. req:: + :id: R-44569 + :target: XNF + :keyword: MUST NOT + + The xNF provider **MUST NOT** require additional + infrastructure such as a xNF provider license server for xNF provider + functions and metrics. + +.. req:: + :id: R-13613 + :target: VNF + :keyword: MUST + + The VNF **MUST** provide clear measurements for licensing + purposes to allow automated scale up/down by the management system. + +.. req:: + :id: R-27511 + :target: VNF + :keyword: MUST + + The VNF provider **MUST** provide the ability to scale + up a VNF provider supplied product during growth and scale down a + VNF provider supplied product during decline without "real-time" + restrictions based upon VNF provider permissions. + +.. req:: + :id: R-85991 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** provide a universal license key + per xNF to be used as needed by services (i.e., not tied to a VM + instance) as the recommended solution. The xNF provider may provide + pools of Unique xNF License Keys, where there is a unique key for + each xNF instance as an alternate solution. Licensing issues should + be resolved without interrupting in-service xNFs. + +.. req:: + :id: R-47849 + :target: XNF + :keyword: MUST + + The xNF provider **MUST** support the metadata about + licenses (and their applicable entitlements) as defined in this + document for xNF software, and any license keys required to authorize + use of the xNF software. This metadata will be used to facilitate + onboarding the xNF into the ONAP environment and automating processes + for putting the licenses into use and managing the full lifecycle of + the licenses. The details of this license model are described in + Tables C1 to C8 in the Appendix. + + Note: License metadata support in ONAP is not currently available + and planned for 1Q 2018. + .. |image0| image:: Data_Model_For_Event_Records.png :width: 7in @@ -269,4 +594,3 @@ Licensing Requirements .. |image3| image:: Protocol_Buffers_Driven_Model.png :width: 4.74in :height: 3.3in - -- cgit 1.2.3-korg