Cisco NME-16ES-1G - Etherswitch Service Mod 16 Specification sheet

Corporate Headquarters:
Copyright © 2005 Cisco Systems, Inc. All rights reserved.
Cisco Systems, Inc., 170 West Tasman Drive, San Jose, CA 95134-1706 USA
Cisco EtherSwitch Service Modules Feature
Guide
Note This document describes the Cisco EtherSwitch service module only. For information about the Cisco
Ethernet switch network module, see “Connecting Ethernet Switch Network Modules to a Network” at
the following URL:
http://www.cisco.com/en/US/products/hw/modules/ps2797/products_module_installation_guide_chapt
er09186a00800b168c.html
The Cisco EtherSwitch service modules (NME-16ES-1G, NME-16ES-1G-P, NME-X-23ES-1G,
NME-X-23ES-1G-P, NME-XD-48ES-2S-P, and NME-XD-24ES-1S-P) provide Cisco modular access
routers the ability to stack Cisco EtherSwitch service modules as Layer 2 switches using Cisco
StackWise technology. The Cisco EtherSwitch service modules are supported by either the IP base image
(formerly known as standard multilayer image [SMI]) or the IP services image (formerly known as the
enhanced multilayer image [EMI]). The IP base image provides Layer 2+ features, including access
control lists (ACLs), quality of service (QoS), static routing, and the Routing Information Protocol
(RIP). The IP services image provides a richer set of enterprise-class features, including Layer 2+
features and full Layer 3 routing (IP unicast routing, IP multicast routing, and fallback bridging). To
distinguish it from the Layer 2+ static routing and RIP, the IP services image includes protocols such as
the Enhanced Interior Gateway Routing Protocol (EIGRP) and the Open Shortest Path First (OSPF)
Protocol.
Feature History for the Cisco EtherSwitch Service Modules (NME-16ES-1G-P, NME-X-23ES-1G-P,
NME-XD-24ES-1S-P, NME-XD-48ES-2S-P)
Feature History for the Cisco EtherSwitch Service Modules (NME-16ES-1G, NME-X-23ES-1G)
Release Modification
12.2(25)EZ (switch software) This feature was introduced.
12.3(14)T (router software) This feature was introduced.
Release Modification
12.2(25)SEC (switch software) This feature was introduced.
12.3(14)T3 (router software) This feature was introduced.

Cisco EtherSwitch Service Modules Feature Guide
Contents
2
Cisco IOS Release 12.2(25)SEC
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image
support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on
Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at
the login dialog box and follow the instructions that appear.
Contents
•Prerequisites for the Cisco EtherSwitch Service Modules, page 2
•Information About the Cisco EtherSwitch Service Modules, page 2
•How to Configure the Cisco EtherSwitch Service Module, page 33
•How to Configure the Cisco EtherSwitch Service Module in a Switch Stack, page 50
•How to Configure a Switch Cluster, page 57
•Upgrading the Cisco EtherSwitch Service Module Software, page 63
•Troubleshooting the Cisco EtherSwitch Service Module Software, page 66
•Switch Stack Configuration Scenarios, page 78
•Network Configuration Examples, page 81
•Additional References, page 87
Prerequisites for the Cisco EtherSwitch Service Modules
The Cisco IOS version on the Cisco EtherSwitch service modules must be compatible with the Cisco
IOS software release and feature set on the router. See the “Feature History for the Cisco EtherSwitch
Service Modules (NME-16ES-1G-P, NME-X-23ES-1G-P, NME-XD-24ES-1S-P,
NME-XD-48ES-2S-P)” section on page 1 and the “Feature History for the Cisco EtherSwitch Service
Modules (NME-16ES-1G, NME-X-23ES-1G)” section on page 1.
•To view the router, Cisco IOS software release and feature set, enter the show version command in
privileged EXEC mode.
•To view the Cisco EtherSwitch service module IOS version, enter the dir flash: command in
privileged EXEC mode.
Information About the Cisco EtherSwitch Service Modules
This section describes the features and some important concepts about the Cisco EtherSwitch service
modules:
•Hardware Overview, page 3
•Software Features and Benefits, page 4
•Cisco StackWise Concepts, page 12
•Clustering Concepts, page 20

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
3
Cisco IOS Release 12.2(25)SEC
Hardware Overview
Cisco EtherSwitch service modules are modules to which you can connect devices such as Cisco IP
phones, Cisco wireless access points, workstations, and other network devices such as servers, routers,
and switches.
Note Cisco EtherSwitch service module models NME-16ES-1G and NME-X-23ES-1G do not support IP
phones.
The Cisco EtherSwitch service modules can be deployed as backbone switches, aggregating 10BASE-T,
100BASE-TX, and 1000BASE-T Ethernet traffic from other network devices.
You can manage the Cisco EtherSwitch service modules as a single switch unit or as a set of switches
forming a switching stack that acts as a single entity. The stacking ports on the Cisco StackWise
EtherSwitch NME-XD-24ES-1S-P service module are used to connect the switches or other Cisco
EtherSwitch service modules in a stack. If the Cisco EtherSwitch service modules are not connected
using Cisco StackWise ports, the Cisco EtherSwitch service modules are managed individually. For
information about which Cisco routers support the Cisco EtherSwitch service modules, see the Cisco
Network Modules Hardware Installation Guide.
Note • You can install only one Cisco StackWise EtherSwitch NME-XD-24ES-1S-P service module in a
single router chassis.
•You can install up to two Cisco EtherSwitch service modules in a single router chassis (in Cisco
3845, Cisco 3825, Cisco 2851, and Cisco 2821 routers) or up to four Cisco EtherSwitch
NME-16ES-1G-P service modules in the Cisco 3745 or Cisco 3845 routers.
•Installing more than two Cisco EtherSwitch service modules in a router chassis requires specific
cabling. For information about cabling multiple Cisco EtherSwitch service modules, see the Cisco
Network Modules Hardware Installation Guide at the following URL:
http://www.cisco.com/en/US/products/hw/modules/ps2797/products_module_installation_guide_b
ook09186a00802d2910.html
The six types of Cisco EtherSwitch service modules are:
•NME-16ES-1G—Standard single-wide Cisco EtherSwitch service module with 16 10/100-Mbps
ports, and 1 10/100/1000 Gigabit Ethernet port.
•NME-16ES-1G-P—Standard single-wide Cisco EtherSwitch service module with 16 10/100-Mbps
ports with Power over Ethernet (PoE), and 1 10/100/1000 Gigabit Ethernet port.
Note The 10/100/1000 Gigabit Ethernet port on the 16-port Cisco EtherSwitch service module
does not support PoE.
•NME-X-23ES-1G—Extended single-wide Cisco EtherSwitch service module with
23 10/100-Mbps ports and 1 10/100/1000 Gigabit Ethernet port.
•NME-X-23ES-1G-P—Extended single-wide Cisco EtherSwitch service module with
23 10/100-Mbps PoE ports and 1 10/100/1000 Gigabit Ethernet port. All ports support PoE.

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
4
Cisco IOS Release 12.2(25)SEC
•NME-XD-48ES-2S-P—Extended double-wide Cisco EtherSwitch service module with
48 10/100-Mbps PoE ports, and 2 small form-factor pluggable (SFP) Gigabit Ethernet service
module ports
•NME-XD-24ES-1S-P—Extended double-wide Cisco EtherSwitch service module with
24 10/100-Mbps PoE ports, 1 SFP port, and 2 Cisco StackWise ports
For complete information about the Cisco EtherSwitch service modules hardware, see the Cisco Network
Modules Hardware Installation Guide at the following URL:
http://www.cisco.com/en/US/products/hw/modules/ps2797/products_module_installation_guide_book
09186a00802d2910.html
Software Features and Benefits
The Cisco EtherSwitch service modules are shipped with either of these software images installed:
•IP base image, which provides Layer 2+ features (enterprise-class intelligent services). These
features include access control lists (ACLs), quality of service (QoS), static routing, and the Hot
Standby Router Protocol (HSRP) and the Routing Information Protocol (RIP). Cisco EtherSwitch
service modules with the IP base image installed can be upgraded to the IP services image.
•IP services image, which provides a richer set of enterprise-class intelligent services. It includes all
IP base image features plus full Layer 3 routing (IP unicast routing, IP multicast routing, and
fallback bridging). To distinguish it from the Layer 2+ static routing and RIP, the IP services image
includes protocols such as the Enhanced Interior Gateway Routing Protocol (EIGRP) and the Open
Shortest Path First (OSPF) Protocol.
Some features noted in this section are available only on the cryptographic versions of the IP base image
and IP services image. You must obtain authorization to use this feature and to download the
cryptographic version of the software from Cisco.com.
The Cisco EtherSwitch service module has these features and benefits:
•Ease-of-Use and Ease-of-Deployment Features, page 5
•Performance Features, page 5
•Management Options, page 6
•Manageability Features, page 7
•Availability Features, page 7
•VLAN Features, page 8
•Security Features, page 9
•QoS and CoS Features, page 10
•Power-over-Ethernet Features, page 11
•Monitoring Features, page 11

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
5
Cisco IOS Release 12.2(25)SEC
Ease-of-Use and Ease-of-Deployment Features
•Express Setup for quickly configuring a Cisco EtherSwitch service module for the first time with
basic IP information, contact information, Cisco EtherSwitch service module and Telnet passwords,
and Simple Network Management Protocol (SNMP) information through a browser-based program.
•Graphical user interfaces (GUIs) for easier Cisco EtherSwitch service module configuration and
monitoring. For more information about these GUIs, see the “Management Options” section on
page 6.
•User-defined and Cisco-default SmartPorts macros for creating custom Cisco EtherSwitch service
module configurations for simplified deployment across the network.
•Cisco StackWise technology for these uses:
– Connecting up to nine Cisco EtherSwitch service modules through Cisco StackWise ports and
operating as a single switch in the network.
– Using a single IP address and configuration file to manage the entire switch stack.
– Automatic Cisco IOS software version-check of new stack members with the option to
automatically load images from the stack master or from a TFTP server.
– Adding, removing, and replacing Cisco EtherSwitch service modules in the stack without
disrupting the operation of the stack.
– Provisioning a new member for a switch stack with the offline configuration feature. You can
configure the interface configuration for a specific stack member number in advance. The
switch stack retains this information across stack reloads whether or not the provisioned
Cisco EtherSwitch service module is part of the stack.
– Displaying stack-ring activity statistics (the number of frames sent by each stack member to the
ring).
Performance Features
•Autosensing of port speed and autonegotiation of duplex mode on all Cisco EtherSwitch service
module ports for optimizing bandwidth
•Automatic-medium-dependent interface crossover (Auto-MDIX) capability on 10/100-Mbps
interfaces that enables the interface to automatically detect the required cable connection type
(straight-through or crossover) and to configure the connection appropriately
•Up to 32 Gbps of forwarding rates in a switch stack
•EtherChannel for enhanced fault tolerance and for providing up to 800 Mbps (Fast EtherChannel)
of full-duplex bandwidth between Cisco EtherSwitch service modules, routers, and servers
•Port Aggregation Protocol (PAgP) and Link Aggregation Control Protocol (LACP) for automatic
creation of EtherChannel links
•Forwarding of Layer 2 and Layer 3 packets at gigabit-per-second line rate across the
Cisco EtherSwitch service modules in the stack
•Per-port storm control for preventing broadcast, multicast, and unicast storms
•Port blocking on forwarding unknown Layer 2 unknown unicast, multicast, and bridged broadcast
traffic

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
6
Cisco IOS Release 12.2(25)SEC
•Cisco Group Management Protocol (CGMP) server support and Internet Group Management
Protocol (IGMP) snooping for IGMP versions 1, 2, and 3:
– (For CGMP devices) CGMP for limiting multicast traffic to specified end stations and reducing
overall network traffic
– (For IGMP devices) IGMP snooping for efficiently forwarding multimedia and multicast traffic
•IGMP report suppression for sending only one IGMP report per multicast router query to the
multicast devices (supported only for IGMPv1 or IGMPv2 queries)
•Multicast VLAN registration (MVR) to continuously send multicast streams in a multicast VLAN
while isolating the streams from subscriber VLANs for bandwidth and security reasons
•IGMP filtering for controlling the set of multicast groups to which hosts on a Cisco EtherSwitch
service module port can belong
•IGMP throttling for configuring the action when the maximum number of entries is in the IGMP
forwarding table
Management Options
•Device manager—The device manager provides simplified management for a single
Cisco EtherSwitch service module. Its features, such as SmartPorts and color-coded graphs, make
it easier to configure and monitor the Cisco EtherSwitch service module. The device manager is
already installed on the Cisco EtherSwitch service module. After the Cisco EtherSwitch service
module is configured through the Express Setup program or through the CLI-based setup program,
the device manager is accessible through a Microsoft Internet Explorer or Netscape Navigator
browser session. For more information, see the device manager online help.
•Cisco Network Assistant—Cisco Network Assistant provides a comprehensive set of features for
managing single and multiple devices, including Cisco EtherSwitch service module clusters,
through a GUI. This application must be downloaded from Cisco.com and installed on your PC. You
can learn more about Network Assistant at this URL:
http://www.cisco.com/go/NetworkAssistant
•CLI—The Cisco IOS CLI software is enhanced to support desktop-switching and
multilayer-switching features. You can access the CLI either by connecting your management
station directly to the Cisco EtherSwitch service module console port or by using Telnet from a
remote management station. You can manage the switch stack by connecting to the console port of
any stack member. For more information about the Cisco EtherSwitch service module CLI, see the
Catalyst 3750 Switch Command Reference, Cisco IOS Release 12.2 at the following URL:
http://www.cisco.com/en/US/products/hw/switches/ps5023/prod_command_reference_list.html
•SNMP—SNMP management applications such as CiscoWorks2000 LAN Management Suite (LMS)
and HP OpenView. You can manage from an SNMP-compatible management station that is running
platforms such as HP OpenView or SunNet Manager. The Cisco EtherSwitch service module
supports a comprehensive set of MIB extensions and four remote monitoring (RMON) groups. For
more information about using SNMP, see the Catalyst 3750 Switch Software Configuration Guide,
Cisco IOS Release 12.2 at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/index.htm

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
7
Cisco IOS Release 12.2(25)SEC
Manageability Features
Note The encrypted Secure Shell (SSH) feature listed in this section is available only on the cryptographic
versions of the Cisco EtherSwitch service module software image.
•Cisco IE 2100 Series CNS embedded agents for automating Cisco EtherSwitch service module
management as well as configuration storage and delivery.
•Dynamic Host Configuration Protocol (DHCP) for automating configuration of Cisco EtherSwitch
service module information (such as IP address, default gateway, hostname, and Domain Name
System [DNS] and Trivial File Transfer Protocol [TFTP] server names)
•DHCP relay agent information (option 82) for subscriber identification and IP address management
•DHCP relay for forwarding User Datagram Protocol (UDP) broadcasts, including IP address
requests, from DHCP clients
•DHCP server for automatic assignment of IP addresses and other DHCP options to IP hosts
•Directed unicast requests to a DNS server for identifying a Cisco EtherSwitch service module
through its IP address and its corresponding hostname and to a TFTP server for administering
software upgrades from a TFTP server
•Address Resolution Protocol (ARP) for identifying a Cisco EtherSwitch service module through its
IP address and its corresponding Media Access Control (MAC) address
•Unicast MAC address filtering to drop packets with specific source or destination MAC addresses
•Cisco Discovery Protocol (CDP) versions 1 and 2 for network topology discovery and mapping
between the Cisco EtherSwitch service module and other Cisco devices on the network
•Network Time Protocol (NTP) for providing a consistent time stamp to all Cisco EtherSwitch
service modules from an external source
•Cisco IOS File System (IFS) for providing a single interface to all file systems that the
Cisco EtherSwitch service module uses
•In-band management access for up to 16 simultaneous Telnet connections for multiple CLI-based
sessions over the network
•In-band management access for up to five simultaneous, encrypted SSH connections for multiple
CLI-based sessions over the network (requires the cryptographic versions of the Cisco EtherSwitch
service module software image)
•In-band management access through SNMP versions 1 and 2c, and 3 GET and SET requests
Availability Features
•HSRP for command Cisco EtherSwitch service module and Layer 3 router redundancy.
•Automatic stack master re-election for replacing stack masters that become unavailable (failover
support).
The newly elected stack master begins accepting Layer 2 traffic in less than 1 second and Layer 3
traffic between 3 to 5 seconds.
•Cross-stack EtherChannel for providing redundant links across the switch stack.
•UniDirectional Link Detection (UDLD) and aggressive UDLD for detecting and disabling
unidirectional links on fiber-optic interfaces caused by incorrect fiber-optic wiring or port faults.

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
8
Cisco IOS Release 12.2(25)SEC
•IEEE 802.1D Spanning Tree Protocol (STP) for redundant backbone connections and loop-free
networks. STP has these features:
– Up to 128 spanning-tree instances supported.
– Per-VLAN spanning-tree plus (PVST+) for balancing load across VLANs.
– Rapid PVST+ for balancing load across VLANs and providing rapid convergence of
spanning-tree instances.
– UplinkFast, cross-stack UplinkFast, and BackboneFast for fast convergence after a
spanning-tree topology change and for achieving load balancing between redundant uplinks,
including gigabit uplinks and cross-stack gigabit uplinks.
•IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) for grouping VLANs into a spanning-tree
instance and for providing multiple forwarding paths for data traffic and load balancing and
IEEE 802.1w Rapid Spanning Tree Protocol (RSTP) for rapid convergence of the spanning tree by
immediately transitioning root and designated ports to the forwarding state.
•Optional spanning-tree features available in PVST+, rapid PVST+, and MSTP mode:
– Port Fast for eliminating the forwarding delay by enabling a port to immediately transition from
the blocking state to the forwarding state.
– BPDU guard for shutting down Port Fast-enabled ports that receive bridge protocol data units
(BPDUs).
– BPDU filtering for preventing a Port Fast-enabled port from sending or receiving BPDUs.
– Root guard for preventing switches outside the network core from becoming the spanning-tree
root.
– Loop guard for preventing alternative or root ports from becoming designated ports because of
a failure that leads to a unidirectional link.
•Equal-cost routing for link-level and Cisco EtherSwitch service module-level redundancy.
•Redundant power supply (RPS) support through the Cisco 2811, 2821, 2851, 3825, and 3845
integrated services routers (ISR). When an AC-IP power supply is installed, RPS is available for
ISRs as well as PoE.
VLAN Features
•Support for VLAN IDs in the full 1 to 4094 range allowed by the IEEE 802.1Q standard.
•The VLAN ID to which the port belongs (also known as its VLAN membership). The default is 1
for all ports.
•VLAN Query Protocol (VQP) for dynamic VLAN membership.
•Inter-Switch Link (ISL) and IEEE 802.1Q trunking encapsulation on all ports for network moves,
adds, and changes; management and control of broadcast and multicast traffic; and network security
by establishing VLAN groups for high-security users and network resources.
•Dynamic Trunking Protocol (DTP) for negotiating trunking on a link between two devices and for
negotiating the type of trunking encapsulation (802.1Q or ISL) to be used.
•VLAN Trunking Protocol (VTP) and VTP pruning for reducing network traffic by restricting
flooded traffic to links destined for stations receiving the traffic.

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
9
Cisco IOS Release 12.2(25)SEC
•Voice VLAN for creating subnets for voice traffic from Cisco IP phones.
•VLAN 1 minimization for reducing the risk of spanning-tree loops or storms by allowing VLAN 1
to be disabled on any individual VLAN trunk link. With this feature enabled, no user traffic is sent
or received on the trunk. The Cisco EtherSwitch service module CPU continues to send and receive
control protocol frames.
Security Features
Note The Kerberos feature listed in this section is available only on the cryptographic versions of the
Cisco EtherSwitch service module software image.
•Password-protected access (read-only and read-write access) to management interfaces for
protection against unauthorized configuration changes
•Multilevel security for a choice of security level, notification, and resulting actions
•Static MAC addressing for ensuring security
•Protected port option for restricting the forwarding of traffic to designated ports on the same
Cisco EtherSwitch service module
•Port security option for limiting and identifying MAC addresses of the stations allowed to access
the port
•Port security aging to set the aging time for secure addresses on a port
•BPDU guard for shutting down a Port Fast-configured port when an invalid configuration occurs
•Standard and extended IP access control lists (ACLs) for defining security policies in both directions
on routed interfaces (router ACLs) and VLANs and inbound on Layer 2 interfaces (port ACLs)
•Extended MAC access control lists for defining security policies in the inbound direction on Layer 2
interfaces
•VLAN ACLs (VLAN maps) for providing intra-VLAN security by filtering traffic based on
information in the MAC, IP, and TCP/User Datagram Protocol (UDP) headers
•Source and destination MAC-based ACLs for filtering non-IP traffic
•DHCP snooping to filter untrusted DHCP messages between untrusted hosts and DHCP servers
•IEEE 802.1x port-based authentication to prevent unauthorized devices (clients) from gaining
access to the network
– 802.1x with VLAN assignment for restricting 802.1x-authenticated users to a specified VLAN
– 802.1x with port security for controlling access to 802.1x ports
– 802.1x with voice VLAN to permit IP phone access to the voice VLAN regardless of the
authorized or unauthorized state of the port
– 802.1x with guest VLAN to provide limited services to non-802.1x-compliant users
•TACACS+, a proprietary feature for managing network security through a TACACS server
•RADIUS for verifying the identity of, granting access to, and tracking the actions of remote users
through authentication, authorization, and accounting (AAA) services

Cisco EtherSwitch Service Modules Feature Guide
Information About the Cisco EtherSwitch Service Modules
10
Cisco IOS Release 12.2(25)SEC
•Kerberos security system to authenticate requests for network resources by using a trusted third
party (requires the cryptographic versions of the Cisco EtherSwitch service module software image)
•802.1Q tunneling to allow customers with users at remote sites across a service provider network to
keep VLANs segregated from other customers, and Layer 2 protocol tunneling to ensure that the
customer network has complete STP, CDP, and VTP information about all users (available on the
Cisco EtherSwitch service module but not on the integrated services router [ISR])
QoS and CoS Features
•Automatic QoS (auto-QoS) to simplify the deployment of existing QoS features by classifying
traffic and configuring egress queues (voice over IP only).
•Cross-stack QoS for configuring QoS features on Cisco EtherSwitch service modules in a switch
stack rather than on an individual Cisco EtherSwitch service module basis.
•Classification
– Classification on a physical interface or on a per-port per-VLAN basis.
– IP type-of-service/differentiated services code point (IP ToS/DSCP) and 802.1p CoS marking
priorities on a per-port basis for protecting the performance of mission-critical applications.
– IP ToS/DSCP and 802.1p CoS marking based on flow-based packet classification (classification
based on information in the MAC, IP, and TCP/UDP headers) for high-performance quality of
service at the network edge, allowing for differentiated service levels for different types of
network traffic and for prioritizing mission-critical traffic in the network.
– Trusted port states (CoS, DSCP, and IP precedence) within a QoS domain and with a port
bordering another QoS domain.
– Trusted boundary for detecting the presence of a Cisco IP phone, trusting the CoS value
received, and ensuring port security.
•Policing
– Policing on a physical interface or on a per-port per-VLAN basis.
– Traffic-policing policies on the Cisco EtherSwitch service module port for managing how much
of the port bandwidth should be allocated to a specific traffic flow.
– Aggregate policing for policing traffic flows in aggregate to restrict specific applications or
traffic flows to metered, predefined rates.
•Out-of-profile markdown for packets that exceed bandwidth utilization limits
•Ingress queueing and scheduling
– Two configurable ingress queues for user traffic (one queue can be the priority queue).
– Weighted tail drop (WTD) as the congestion-avoidance mechanism for managing the queue
lengths and providing drop precedences for different traffic classifications.
– Shaped round robin (SRR) as the scheduling service for specifying the rate at which packets are
dequeued to the stack internal ring (sharing is the only supported mode on ingress queues).