Operate and maintain
Documents under this category provide functional descriptions and procedures for configuring, operating, and maintaining 7450 ESS, 7750 SR, 7950 XRS, and VSR routers.
- Advanced Configuration Guides
- Basic System Configuration Guide
  This guide describes file system management, boot option file (BOF) configuration, basic system management configuration, node timing, and synchronization functions.
- BNG CUPS User Plane Function Guide
  This guide describes all aspects related to a Nokia SR OS BNG CUPS User Plane Function (UPF) in a BNG CUPS system.
- BNG CUPS MAG-c documentation
- Interface Configuration Guide
  This guide describes how to provision Input/Output Modules (IOMs), XMA Control Modules (XCMs), Media Dependent Adapters (MDAs), XRS Media Adapters (XMAs), connectors, and ports.
- Layer 2 Services and EVPN Guide
  This guide describes Layer 2 service and Ethernet Virtual Private Network (EVPN) functionality and provides examples to configure and implement Virtual Leased Lines (VLLs), Virtual Private LAN Service (VPLS), Provider Backbone Bridging (PBB), and EVPN.
- Layer 3 Services Guide
  This guide describes Layer 3 service functionality and provides examples to configure and implement Internet Enhanced Services (IES) and Virtual Private Routed Network (VPRN) services.
- MD-CLI User Guide
  This guide provides information about how to use the MD-CLI.
- MPLS Guide
  This guide provides an overview of Multiprotocol Label Switching (MPLS), Resource Reservation Protocol (RSVP), and Label Distribution Protocol (LDP) and provides configuration examples.
- MS-ISA and ESA Guide
  This guide provides an overview of services provided by integrated service adapters and extended service appliances, such as Application Assurance, IPsec, ad insertion (ADI), and Network Address Translation (NAT), and provides configuration examples.
- Multicast Guide
  This guide provides an overview of multicast routing concepts and provides configuration examples for Internet Group Management Protocol (IGMP), Multicast Listener Discovery (MLD), Protocol Independent Multicast (PIM), Multicast Source Discovery Protocol (MSDP), Multipoint LDP, multicast extensions to BGP, and Multicast Connection Admission Control (MCAC).
- Peering Quick Reference Guide
  This guide provides example configuration for a peering router. .
- QoS Guide
  This guide provides an overview of Quality of Service (QoS) policy management and provides configuration examples.
- Router Configuration Guide
  This guide dscribes logical IP routing interfaces and associated attributes such as IP addresses, as well as IP and MAC-based filtering, Virtual Router Redundancy Protocol (VRRP), and cflowd.
- Security Guide
- Segment Routing and PCE User Guide
  This guide provides an overview of segment routing features with MPLS (SR-MPLS) and IPv6 (SRv6) data path encapsulations and path computation element (PCE) features.
- Services Overview Guide
  This guide provides a general overview of functionality provided by the routers and describes how to configure service parameters such as Service Access Points (SAPs), Service Distribution Points (SDPs), customer information, and user services.
- System Management Guide
  This guide describes system security features, SNMP and NETCONF features, and event and accounting logs; the guide also covers basic tasks such as configuring management access filters, passwords, and user profiles.
- TPSDA Guide
  This guide describes the Triple Play Service Delivery Architecture (TPSDA) support and provides examples to configure and implement various protocols and services.
- Unicast Routing Protocols Guide
  This guide provides an overview of unicast routing concepts and provides configuration examples for Routing Information Protocol (RIP), Open Shortest Path First (OSPF), Intermediate-system-to-intermediate-system (IS-IS), and Border Gateway Protocol (BGP) routing protocols; also provides an overview of route policies and configuration examples.

TCP MSS adjustment

Overview

This feature adds support for adjustment of MSS of TCP packets with SYN flag according to access/aggregation network to prevent fragmentation of upstream and downstream TCP packets using ISA-BB.

There are two modes of adjustment operations supported: TCP MSS Adjustment for ESM Hosts, and TCP MSS Adjustment for NAT Services.

For TCP MSS adjust using ISA2-AA, see section AQP for the AQP rules.

TCP MSS adjustment for ESM hosts

This feature adds support for adjustment of the MSS size of TCP packets with SYN flag according to the access/aggregation network to prevent fragmentation of upstream and downstream TCP packets using ISA-BB diverted by IP/IPv6 filter actions.

The following ESM host types are supported:

IPv4/IPv6 IPoE hosts
locally terminated PPPoE hosts (without L2TP LAC)
L2TP LNS hosts

The configuration steps are as follows:

Create a NAT group used for an MSS adjustment.

config>isa
nat-group 1
active-mda-limit 2
mda 1/1
mda 1/2

Associate the NAT group with a routing instance and configure the MSS value.
```
config>router
config>service>vprn
mss-adjust-group 1 segment-size 1452
```
Note: Unless there are dedicated ISAs or ESAs for MSS adjustment, an existing NAT group or WLAN-GW group can be referenced. If multiple NAT or WLAN-GW groups reference the same ISA or ESA, the NAT or WLAN-GW groups become inactive. MSS adjustment does not function correctly if it references an inactive NAT or WLAN-GW group.

Create an IPv4/IPv6 filter to perform an MSS adjust.

config>filter>ip-filter>entry
egress-pbr default-load-balancing
match tcp-syn
action tcp-mss-adjust
config>filter>ipv6-filter>entry
match tcp-syn
action tcp-mss-adjust

Apply an IPv4/IPv6 filter to the SLA profile.

TCP MSS adjustment for NAT services

This feature provides MSS adjustment for TCP packets to be translated by NAT services.

The configuration steps are as follows:

Create a NAT-group used for NAT services with MSS adjustment.

config>isa
   nat-group 1
      active-mda-limit 2
      mda 1/1
      mda 1/2

Create a NAT-policy that also adjusts MSS.

config>service>nat
   nat-policy "policy-for-mss-adjust" crate
      tcp-mss-adjust 1452

October 31, 2023