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ME60 V800R010C10SPC500 Feature Description - System Management 01

This is ME60 V800R010C10SPC500 Feature Description - System Management
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Restarting devices is required during software upgrade and maintenance on most networks. However, the restart interrupts services and deteriorates system performance.

A solution to the problem is to establish an equal-cost multiple path (ECMP) and switch service traffic to a backup path during a software upgrade. In this situation, network configurations must be modified, which increases the failure probability and prolongs the upgrade period. The other effect is that services may be interrupted when a backup path is over-crowded after the service switchover.

In-Service Software Upgrade (ISSU) is a convenient and rapid software upgrade mode that upgrades the system software on a device. ISSU is used for planned software upgrade of network devices. It effectively shortens the service interruption period and improves service reliability.

Users cannot specify the source and target versions at random for ISSU. The two versions need to be planned and developed in advance. For details about ISSU target versions supported by the current version, contact Huawei R&D engineers.

Hardware replacement is not allowed during the ISSU upgrade.

ISSU Process

There is no or little impact on services because an ISSU does not require the entire device to restart. Only partial system switchover is required using the NSF and NSR features of services.

As shown in Figure 6-2, an ISSU process consists of three phases, completed in the following order: check, start, and confirm.
  1. ISSU check: checks whether an ISSU can be performed and the ISSU type.
  2. ISSU start: a main phase of an ISSU. In this phase, the master and slave MPUs and LPUs are upgraded to the target version.
  3. ISSU confirm/abort: confirms or aborts an ISSU.
    • ISSU confirm: confirms an ISSU result.
    • ISSU abort: aborts an ISSU. The entire device is restarted and rolled back to the old version, which interrupts services.
Figure 6-2 Schematic diagram of an ISSU process

Table 6-3 shows the details.

Table 6-3 ISSU process

ISSU Phase

Schematic Diagram for Each Phase


ISSU check

Figure 6-3 ISSU check

In this phase, the system performs a compatibility check, such as on the version number and specifications, to check whether ISSU can be used and determine the upgrade mode to be used.

ISSU start

Figure 6-4 ISSU start in fast restart mode

ISSU confirm

Figure 6-5 ISSU confirm

As shown in Figure 6-5, the new system software is specified as the software for the next startup during the ISSU confirm phase.


ISSU offers the following benefits for operators: The network topology does not need to be changed during an ISSU process. All devices that support ISSU on the network can be upgraded. ISSU decreases the operating expenditure (OPEX).

ISSU also offers benefits for users. It shortens the voice or data service interruption period and improves user experience.

Updated: 2019-01-04

Document ID: EDOC1100059466

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