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Intelligent Services Gateway (ISG) is a Cisco IOS XE software feature set that provides a structured framework in which edge devices can deliver flexible and scalable services to subscribers. This module describes the IPv6 support available for ISG IP subscriber sessions including information about the Time-Based Billing feature.
Out-of-band IPv6 sessions are not supported, which means DHCP initiated or RADIUS proxy initiated sessions are not supported for IPv6 sessions.
Time-based billing is not supported on PPP sessions directly; it is supported through services and flows installed on the PPP session
ISG creates an IPv6 subscriber session based on the first IPv6 packet received from an unclassified IPv6 address or IPv6 prefix, similar to the way subscriber sessions are created for IPv4 packets. The subscriber session is identified by the IPv6 address. Native IP sessions have either an IPv4 or IPv6 address, but not both. A native IPv6 session has an IPv6 address only and all traffic generated from the subscriber uses IPv6.
IPv6 single-stack sessions are supported for ISG subscriber sessions. If a native IP subscriber’s host sends traffic for both an IPv4 and IPv6 address, ISG creates a separate IP session for each of these IP addresses. This subscriber will have an IPv4 session and an IPv6 session with no interaction between them. A dual-stack session is a single subscriber session with two distinct IP addresses, one for IPv4 and one for IPv6. Dual-stack native IP sessions are not supported.
Layer 3 unclassified IPv6 sessions for routed subscribers are supported. These sessions are identified by their unique IPv6 IP address or an IPv6 subnet session (IPv6 address and prefix). IPv6 is not supported for Layer 2 connected and DHCP-initiated subscriber sessions.
The following session combinations can exist on the same ISG interface in Cisco IOS XE Release 3.5S and later releases:
Native IPv6 and native IPv4 sessions
Native IPv6 and PPP IPv4 sessions
Native IPv6 and PPP IPv6 sessions
Native IPv6 and PPP dual-stack sessions
Dual-stack features are protocol independent and work at the session level. These features cannot be configured based on the stack. A single generic configuration is applied to the session regardless of whether it is a single-stack or dual-stack session. The configuration of these features is the same for IPv4 and IPv6.
Because these features are applied at the session level, the same instance of the feature handles both the IPv4 and IPv6 stacks for a dual-stack session, and the behavior is aggregated. For example, the same instance of the accounting feature counts both IPv4 and IPv6 packets. Similarly, the same instance of the idle timeout feature monitors both IPv4 and IPv6 traffic and considers a session to be idle when there is neither type of traffic.
The following features are examples of dual-stack features:
Absolute Timeout (Session Timer)
Idle Timeout (Connection Timer)
ISG Accounting
ISG Policer (Dynamic Rate Limiting)
Quality of Service
Protocol-dependent features rely on the underlying protocol. An instance of the feature works only for one of the protocols, either IPv6 or IPv4. For example, the Layer 4 Redirect feature has translation rules that are protocol dependent. An IPv6 packet can be redirected only to an IPv6 destination; an IPv4 packet can be redirected only to an IPv4 destination.
The configuration of protocol-dependent features applies only to the corresponding stack of the session. If a feature must run on both protocols for a dual-stack session, separate configurations must be created and applied on both stacks respectively. These features cannot be configured for an entire session unless it is a single-stack session.
The behavior of protocol-dependent features is limited to a single stack. An instance of the feature runs only on a particular stack and has no functional impact on the other stack, if applicable. If the feature is applied on both stacks of a dual-stack session, two separate instances are created and run independently. There is no aggregated behavior for these features.
The following features are examples of ISG protocol-dependent features:
Access Control Lists (ACLs)
Layer 4 Redirect
Port-Bundle Host Key
Traffic Classes
The following ISG features are supported for native IPv6 sessions and PPP dual-stack sessions:
|
Feature |
Description |
Session Support |
|---|---|---|
|
Absolute Timeout (Session Timer) |
IPv6 functionality and configuration are the same as for IPv4 subscriber sessions. For configuration information, see the “Configuring ISG Policies for Session Maintenance” module in this guide. |
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Idle Timeout (Connection Timer) |
IPv6 functionality and configuration are the same as for IPv4 subscriber sessions. For configuration information, see the “Configuring ISG Policies for Session Maintenance” module in this guide. |
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|
ISG Accounting |
Per-session and per-service accounting can be configured on either an IPv4-only or IPv6-only IP session. Per-flow accounting can be configured on either an IPv4 or IPv6 traffic class. For configuration information, see the “Configuring ISG Accounting” module in this guide. |
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ISG Policer (Dynamic Rate Limiting) |
IPv6 functionality and configuration are the same as for IPv4 subscriber sessions. For information, see the “Configuring MQC Support for IP Sessions” module in this guide. |
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Layer 4 Redirect |
IPv6 packets can be redirected only to an IPv6 destination; IPv4 packets can be redirected only to an IPv4 destination. For configuration information, see the “Redirecting Subscriber Traffic Using ISG Layer 4 Redirect” module in this guide. |
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|
Modular QoS CLI (MQC) |
The following operations are supported for an MQC policy applied to PPP IPv6 sessions and PPP dual-stack sessions:
For configuration information, see the “Configuring MQC Support for IP Sessions” module in this guide. |
|
|
Traffic Classes |
The protocol version of a traffic class is determined by the protocol version of the access control list (ACL) that was used to configure the traffic class. IPv6 traffic classes are supported using named IPv6 ACLs. Traffic classes are also supported on PPP sessions. For configuration information, see the “Configuring ISG Subscriber Services” module in this guide. |
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The Time-Based Billing feature calculates the 24-hour volume usage for all subscriber sessions that are active on an L2TP network server (LNS) at a specified time each day. It reports the volume used by a session since the last specified time, in 24-hour intervals. You can configure the router to collect the volume statistics of all active sessions at the same time every day, for example, everyday at midnight. The system would report the volume usage of a session from midnight of the previous day to midnight of the current day.
Time-based billing will also report input and output traffic statistics for IPv6 and IPv4 traffic separately and as an aggregate using new AAA attributes in AAA accounting records.
Changes in local time based on Day Light Savings Time (DST), Network Time Protocol (NTP), or clock changes configured on the router are taken into account when reporting volume statistics at the specified time.
Time-based billing is supported for IPv4, IPv6, and PPP sessions.
 Note |
IPv6 sessions for Layer 2 connected subscribers are not supported. |
To enable ISG to create an IPv6 subscriber session after receiving the first packet with a particular IPv6 prefix, you define the IPv6 prefix in an IP subscriber list.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
ip subscriber list list-name Example: |
Specifies the IP subscriber list name and enters server list configuration mode. |
|
Step 4 |
ipv6 prefix default length Example: |
Defines the IPv6 prefix for which ISG initiates IPv6 subscriber sessions. |
|
Step 5 |
exit Example: |
Returns to global configuration mode. |
|
Step 6 |
interface type number Example: |
Specifies an interface and enters interface configuration mode. |
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Step 7 |
ip subscriber routed Example: |
Specifies that routed IP subscribers are to be hosted on the interface and enters ISG IP subscriber configuration mode. |
|
Step 8 |
initiator unclassified ip-address [ipv6] [list list-name] Example: |
Enables ISG to create an IPv6 subscriber session after receiving a packet with the IPv6 prefix. |
|
Step 9 |
end Example: |
Returns to privileged EXEC mode. |
ISG time-based billing is configured in the service profile on a AAA server. If you include a traffic class in the service profile, time-based billing will apply to the specified flow. If you do not configure a traffic class, time-based billing will apply to the session.
ISG per-session or per-flow accounting must be configured.
|
Step 1 |
Cisco-AVpair = “PPWhh :mm :ss :d ” Add the Post Paid VSA to the service profile. This attribute specifies the weekly tariff-billing points as follows: hh :mm :ss :d —Weekly billing time.
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|
Step 2 |
Cisco-AVpair = “ip:traffic-class={in | out} access-group [acl-number | name acl-name ] [priority n ]” Add the ISG traffic class attribute to the service profile. This attribute specifies the input and output traffic to which the service will apply. Both an input and output traffic classifier can be added to a service profile. |
|
Step 3 |
show subscriber session feature time-based-billing detailed Enter this command on the ISG router to display information about time-based billing. The following example shows output from this command: |
The following example shows an IPv6 prefix defined in the IP subscriber list named mylist, which has been assigned to Gigabit Ethernet port 0/0/0. ISG will create an IPv6 subscriber session when it receives the first packet with the default IPv6 prefix.
ip subscriber list mylist
ipv6 prefix default 64
interface GigabitEthernet0/0/0
ip vrf forwarding vrf-1
ip address 10.1.1.1 255.255.255.0
ip access-group 101 out
ip virtual-reassembly
zone-member security private
media-type sfp
negotiation auto
ipv6 address 2001:DB8:1:1::26/64
ip subscriber routed
initiator unclassified ip-address ipv6 list mylistThe following example shows an IPv6 session configured for doing billing daily at midnight:
PPW00:00:00:127Day 1—A native IPv6 session starts at 10 a.m.
Day 1 at tariff-switch point (12 a.m.)—A snapshot of the current volume used from 10 a.m. is recorded, for example:
IPv6-input-bytes = 10000
IPv6-input-packets = 100
IPv6-output-bytes = 20000
IPv6-output-packets= 200Day 2 say at 12:10 a.m.—Interim record is sent. The Interim record will carry the following values in the VSAs:
Tariff-Input-Packets = 100 Aggregate Input IPv4 and IPv6 Packets
Tariff-Input-Octets = 10000 Aggregate Input IPv4 and IPv6 Bytes
Tariff-Input-Packets-IPv6 = 100
Tariff-Input-Octets-IPv6 = 10000
Tariff-Output-Packets = 200 Aggregate Output IPv4 and IPv6 Packets
Tariff-Output-Octets = 20000 Aggregate Output IPv4 and IPv6 Bytes
Tariff-Output-Packets-IPv6 = 200
Tariff-Output-Octets-IPv6 = 200Day 2—All Interim records sent thereafter until the next tariff-switch point will carry the above values.
Day 2 at tariff-switch point (12 a.m.)—A snapshot of the volume used from Day 1 at 12 a.m. to Day 2 at 12 a.m. is recorded, for example:
IPv6-input-bytes = 600000
IPv6-input-packets = 6000
IPv6-output-bytes = 20000
IPv6-output-packets= 200Day 3 say at 12:20 a.m.—Interim record is sent. The Interim record will carry the following values in the VSAs:
Tariff-Input-Packets = 6000 Aggregate Input IPv4 and IPv6 Packets
Tariff-Input-Octets = 600000 Aggregate Input IPv4 and IPv6 Bytes
Tariff-Input-Packets-IPv6 = 6000
Tariff-Input-Octets-IPv6 = 600000
Tariff-Output-Packets = 200 Aggregate Output IPv4 and IPv6 Packets
Tariff-Output-Octets = 20000 Aggregate Output IPv4 and IPv6 Bytes
Tariff-Output-Packets-IPv6 = 200
Tariff-Output-Octets-IPv6 = 200Day 3—All Interim records sent thereafter until the next tariff-switch point will carry the above same values.
Day 4—The session is disconnected at 8 a.m. A snapshot of the volume used from last tariff to the session disconnect time is taken, for example:
IPv6-input-bytes = 500
IPv6-input-packets = 1
IPv6-output-bytes = 400
IPv6-output-packets= 1A stop record is sent with the following values in the VSAs:
Tariff-Input-Packets = 1 Aggregate Input IPv4 and IPv6 Packets
Tariff-Input-Octets = 500 Aggregate Input IPv4 and IPv6 Bytes
Tariff-Input-Packets-IPv6 = 1
Tariff-Input-Octets-IPv6 = 500
Tariff-Output-Packets = 1 Aggregate Output IPv4 and IPv6 Packets
Tariff-Output-Octets = 400 Aggregate Output IPv4 and IPv6 Bytes
Tariff-Output-Packets-IPv6 = 1
Tariff-Output-Octets-IPv6 = 400The following example shows an IPv4 session configured for doing billing daily at midnight:
PPW00:00:00:127Day 1—A native IPv4 session starts at 10 a.m.
Day 1 at tariff-switch point (12 a.m.)—A snapshot of the current volume used from 10 a.m. is recorded, for example:
IPv4-input-bytes = 10000
IPv4-input-packets = 100
IPv4-output-bytes = 20000
IPv4-output-packets= 200Day 2 say at 12:10 a.m.—Interim record is sent. The Interim record will carry the following values in the VSAs:
Tariff-Input-Packets = 100 Aggregate Input IPv4 and IPv6 Packets
Tariff-Input-Octets = 10000 Aggregate Input IPv4 and IPv6 Bytes
Tariff-Output-Packets = 200 Aggregate Output IPv4 and IPv6 Packets
Tariff-Output-Octets = 20000 Aggregate Output IPv4 and IPv6 BytesDay 2—All Interim records sent thereafter until the next tariff-switch point will carry the same above values.
Day 2 at tariff-switch point (12 a.m.)—A snapshot of the volume used from Day 1 at 12 a.m. to Day 2 at 12 a.m. is recorded, for example:
IPv4-input-bytes = 600000
IPv4-input-packets = 6000
IPv4-output-bytes = 20000
IPv4-output-packets= 200Day 3 say at 12:20 a.m.—Interim record is sent. The Interim record will carry the following values in the VSAs:
Tariff-Input-Packets = 6000 Aggregate Input IPv4 and IPv6 Packets
Tariff-Input-Octets = 600000 Aggregate Input IPv4 and IPv6 Bytes
Tariff-Output-Packets = 200 Aggregate Output IPv4 and IPv6 Packets
Tariff-Output-Octets = 20000 Aggregate Output IPv4 and IPv6 BytesDay 3—All Interim records sent thereafter until the next tariff-switch point will carry the same above values.
Day 4—The session is disconnected at 8 a.m. A snapshot of the volume used from the last tariff-switch point to session disconnect time is taken, for example:
IPv4-input-bytes = 500
IPv4-input-packets = 1
IPv4-output-bytes = 400
IPv4-output-packets= 1A stop record is sent with the following values in the VSAs:
Tariff-Input-Packets = 1 Aggregate Input IPv4 and IPv6 Packets
Tariff-Input-Octets = 500 Aggregate Input IPv4 and IPv6 Bytes
Tariff-Output-Packets = 1 Aggregate Output IPv4 and IPv6 Packets
Tariff-Output-Octets = 400 Aggregate Output IPv4 and IPv6 Bytes|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
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ISG commands |
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IPv6 Configuration |
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Configuring ISG accounting |
“Configuring ISG Accounting” module in this guide |
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Configuring ISG timers |
“Configuring ISG Policies for Session Maintenance” module in this guide |
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Configuring Layer 4 redirect |
“Redirecting Subscriber Traffic Using ISG Layer 4 Redirect” module in this guide |
|
Configuring traffic classes |
“Configuring ISG Subscriber Services” module in this guide |
|
Description |
Link |
|---|---|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.|
Feature Name |
Releases |
Feature Information |
||
|---|---|---|---|---|
|
ISG IPv6 Support |
Cisco IOS XE Release 3.4S |
The following commands were introduced or modified: initiator , ipv6 prefix , show ip subscriber , show subscriber session . |
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ISG: IPv6 Support phase II |
Cisco IOS XE Release 3.5S |
Adds support for IPv6 PPP sessions and PPP dual-stack sessions for the following features:
The following commands were introduced or modified: redirect session-limit, redirect to, show redirect group, show redirect translations, server ip . |
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