Cisco Content Services Gateway - 2nd Generation Release 2.0 Installation and Configuration Guide, for Cisco IOS Release 12.4(15)MD - Configuring PSD Support [Cisco Content Services Gateway]

Table Of Contents

Configuring PSD Support

Configuring the PSD Local Port

Configuring the PSD

Configuring the PSD Packet Drain Settings

Configuring the PSD Keepalive Time

Configuring the PSD GTP' Message Buffer

Configuring the PSD Retransmit Time

Configuring the PSD Retry Number

Configuring the PSD Window Size

Configuring PSD Support

The CSG2 supports the Cisco Persistent Storage Device (PSD). The PSD provides persistent storage capabilities to the CSG2, and allows the CSG2 to store data on the PSD's internal hard drive.

Under normal conditions, the CSG2 sends call detail records (CDRs) to the Billing Mediation Agents (BMAs). If for any reason those BMAs cannot be reached, CDRs are sent to the PSD for safekeeping until contact is reestablished with the BMAs. When contact is reestablished, the CSG2 retrieves the CDRs from the PSD and forwards them to the BMAs.

Note Instead of using the PSD as backup storage, the CSG2 can use the Storage Area Network (SAN) connected to the Internet Small Computer Systems Interface (iSCSI). For more information, see the "Configuring iSCSI Support" section on page 8-1.

The CSG2 supports only one type of backup device, either a PSD or an iSCSI device. The PSD and iSCSI features can coexist, but only one can be enabled at a time.

Storage

Under normal conditions, the PSD provides standby capabilities when necessary—for example, during network outages. The PSD stores the payload from the packet in a queue, and is unaware of the content or format of that data, so that the data can be retrieved exactly as it was sent.

Retrieval

Once the CSG2 determines that the regular data server is again reachable (in this case, the BMA), it retrieves the stored data from the PSD. The data is returned to the CSG2 in the same order and form as it was deposited. The CSG2 is responsible for maintaining order, if necessary, or of mixing retrieved data with incoming "live" records. Once the CSG2 acknowledges to the PSD that it has successfully sent the data to the data server (the BMA), the PSD deletes that data. The PSD stores the data until it receives this acknowledgement.

The CSG2 provides the following features for the Cisco Persistent Storage Device (PSD):

•Configuring the PSD Local Port

•Configuring the PSD

•Configuring the PSD Packet Drain Settings

•Configuring the PSD Keepalive Time

•Configuring the PSD GTP' Message Buffer

•Configuring the PSD Retransmit Time

•Configuring the PSD Retry Number

•Configuring the PSD Window Size

Configuring the PSD Local Port

The first step when configuring CSG2 support for the PSD is to configure the local port on which the CSG2 is to communicate with the PSD.

To configure a local port for the PSD, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd local-port port-number
Configures the local port on which the CSG2 communicates with the PSD.

The PSD local port number must be different from the BMA local port number and from the quota server local port number (configured with the ip csg bma local-port command and the ip csg quota-server local-port command, respectively).
Configuring the PSD

You can configure one and only one PSD for each CSG2.

If you have enabled interface awareness, you can also associate a VLAN's Virtual Routing and Forwarding (VRF) table name with the PSD.

To configure a PSD, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd local-port [vrf vrf-name] 
ip-address port-number
Configures the PSD.
Configuring the PSD Packet Drain Settings

When the BMA becomes active, the CSG2 begins draining packets from the PSD.

By default, the CSG2 limits the rate at which GTP' messages are read from the PSD to 500 packets/second. However, you can change that rate. For example, you can specify an interval of 2 seconds to yield a rate of 250 packets/second (500 packets/2 seconds).

To configure a delay before the CSG2 begins draining packets, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd drain delay number-of-seconds
(Optional) Defines the delay interval, in seconds, before draining packets from the PSD when the BMA becomes active.
You can also change the rate at which GTP' messages are read from the PSD by changing the number of packets to be drained per interval. For example, specifying that 1000 packets are to be drained per interval yields a rate of 1000 packets/second (1000 packets/1 second).

To configure the number of packets to be drained from the PSD, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd drain packet number-of-packets
(Optional) Defines the number of packets to be drained from the PSD per drain delay interval when the BMA becomes active.
Configuring the PSD Keepalive Time

By default, the CSG2 sends keepalive messages to the PSD once every 60 seconds. That setting is sufficient in most environments, but the CSG2 also allows you to change the time between keepalive messages, if necessary.

Note We recommend that you change the keepalive time interval only when directed to do so by Cisco Technical Assistance Center (TAC) engineers. In most environments, the default value is the most appropriate setting.

To change the keepalive timer for the PSD, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd keepalive number-of-seconds
(Optional) Defines the PSD keepalive time interval for the CSG2.
Configuring the PSD GTP' Message Buffer

The CSG2 can buffer general packet radio service (GPRS) tunneling protocol prime (GTP') messages for the BMA. For the PSD, the CSG2 can buffer additional GTP' messages, beyond the size of the BMA GTP' message queue. The default settings are sufficient in most environments, but the CSG2 also allows you to change the PSD GTP' message buffer, if necessary.

Note We recommend that you change the number of GTP' messages that can be buffered only when directed to do so by Cisco Technical Assistance Center (TAC) engineers. In most environments, the default value is the most appropriate setting.

To change the maximum number of GTP' messages, beyond the size of the BMA GTP' message queue, that the CSG2 can buffer for the PSD, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd margin number
(Optional) Specifies the maximum number of GTP' messages, beyond the size of the BMA message queue, that the CSG2 can buffer for the PSD.
Configuring the PSD Retransmit Time

By default, the CSG2 retransmits packets to the PSD once every four seconds. That setting is sufficient in most environments, but the CSG2 also allows you to change the time between retransmits, if necessary.

Note We recommend that you change the retransmit time interval only when directed to do so by Cisco Technical Assistance Center (TAC) engineers. In most environments, the default value is the most appropriate setting.

To change the PSD retransmit time interval for the CSG2, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd retransmit number-of-seconds
(Optional) Defines the PSD retransmit time interval for the CSG2.
Configuring the PSD Retry Number

By default, the CSG2 retries communication with the PSD three times before determining that the link has failed. That setting is sufficient in most environments, but the CSG2 also allows you to change the number of retries, if necessary.

Note We recommend that you change the number of retries allowed only when directed to do so by Cisco Technical Assistance Center (TAC) engineers. In most environments, the default value is the most appropriate setting.

To change the maximum number of PSD retries allowed before the CSG2 determines that the link has failed, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd retries number-of-retries
(Optional) Defines the maximum number of PSD retries allowed before the CSG2 determines that the link has failed.
Configuring the PSD Window Size

By default, the CSG2 sets the maximum PSD transmit window size to 128 packets, and sets the minimum PSD transmit window size automatically. Those settings are sufficient in most environments, but the CSG2 also allows you to change the maximum and minimum PSD transmit window sizes, if necessary.

Note We recommend that you change the transmit window size only when directed to do so by Cisco Technical Assistance Center (TAC) engineers. In most environments, the default value is the most appropriate setting.

To define the PSD transmit window size for the CSG2, enter the following command in global configuration mode:
Command

Purpose
csg2(config)# ip csg psd window {max window-size | 
min window-size | min auto}
(Optional) Defines the PSD transmit window size for the CSG2.