Accelerate EMC SRDF/A replication over any WAN and any distance

Data protection is an essential part of business continuity and disaster recovery. EMC Symmetrix Remote Data Facility/Asynchronous (SRDF/A) is a key component for disaster recovery. SRDF/A’s continuous remote replication transfers data sets at defined intervals, making it possible to replicate large amounts of data between geographically separated data centers.

Inefficiencies in long distance WAN connections can undermine SRDF/A replication performance. High latency, bandwidth contention, out-of-order or dropped packets can all result in missed RPOs and potentially failed replication. That’s where Silver Peak can help. 

EMC and Silver Peak

E-Lab Proven

Silver Peak qualifies with EMC SRDF/A as part of the EMC E-Lab, and is listed on the EMC Support Matrix. During qualification, extensive testing is performed to validate use cases, and also characterize the value when Silver Peak and EMC SRDF/A are used together. The performance data below is from the most recent qualification of Silver Peak software with EMC SRDF/A.  

Boosting SRDF/A replication performance in MPLS and IP VPN networks

  • 155 Mbps network connection with 0.1% packet loss
  • Replication before Silver Peak:  
    • In an MPLS WAN with 0.1% packet loss, SRDF/A replicates close to line rate at latency up to 80 ms (Figure 1)
    • In an IP VPN with 1% packet loss, SRDF/A throughput drops as latency increases beyond 20 ms. (Figure 2)
  • Replication with Silver Peak software enabled:
    • In an MPLS WAN, Silver Peak raises SRDF/A replication to 700 Mbps  (Figure 1) 
    • In an IP VPN, Silver Peak raises SRDF/A replication to 650 Mbps (Figure 2)

Figure 1. Replication across 155Mbps MPLS WAN, 0.1% packet loss

Figure 2. Replication across 155Mbps IP VPN, 1% packet loss

Source: Technical paper: Silver Peak Replication Acceleration and EMC SRDF/A

Understanding the Silver Peak advantage

Silver Peak Velocity Replication Acceleration (VRX) software fixes the problems that exist on the WAN, enabling more data to be replicated, in less time, and over longer distances. Silver Peak software solves WAN problems by repairing dropped and out-of-order packets, overcoming the effects of latency, and providing real-time deduplication and compression of all data sent across the WAN. Silver Peak also provides an IPSec VPN that secures replication traffic without impacting performance.
When the problems on the WAN have been repaired, it is easy to meet, maintain, and even reduce RPOs.
With Silver Peak software, EMC SRDF/A can:

  • Protect more data and get consistent, high replication throughput over any network
  • Replicate over longer distances by overcoming latency
  • Maximize available bandwidth for replication
  • Scale to accommodate Enterprise WANs up to 5 Gbps
  • Accelerate replication, backup and data migration without making any changes to the network
  • Encrypt and accelerate SRDF/A traffic using an AES-256, IPSec VPN

Silver Peak’s storage-specific reporting enables any storage professional to easily manage the Silver Peak implementation and get useful information. Reports are in storage-friendly terms showing the data replicated (in bytes) and replication performance. Storage traffic is segmented by type, such as replication and / or backup traffic, and application, like SRDF/A or RecoverPoint. Metrics are reported per minute, per hour, and per day and include a 10 day graph to show changes made over a weekend.
With EMC SRDF/A and Silver Peak Velocity Replication Accelerator (VRX) software, you can protect all of your business-critical data and replicate consistently, regardless of network problems or distance.  


  • Replicate faster. Replicate more data in less time to remote locations.
  • Replicate over longer distances. Eliminate distance limitations between source/target devices.
  • Improve business continuity. Maintain redundant data centers in distant geographies for rapid recovery from disasters.
  • Lower disaster recovery costs. Eliminate costly dedicated networks for replication; avoid bandwidth upgrades.
  • Improve performance over shared WANs. Automatically correct packet delivery problems and prioritize traffic over shared WANs to guarantee network resources




  • Silver Peak VRX Replication Acceleration software makes replication acceleration easy and affordable.
  • The EMC Symmetrix Remote Data Facility / Asynchronous (SRDF/A) is a key component for disaster recovery with EMC Symmetrix storage arrays. SRDF/A provides the technology necessary to replicate large amounts of data between geographically separated data centers. SRDF/A throughput can be severely limited by problems with the WAN connection between the primary and secondary data centers. Limited bandwidth, latency, dropped packet, and out-of-order packets all reduce SRDF/A throughput, causing missed recovery point objectives (RPO) and failed replication.
  • Bed Bath & Beyond is a top retailer, with 930 stores throughout the US and Ontario, Canada. The stores’ floor-to-ceiling shelves stock better-quality (brand-name and private-label) goods in two main categories: domestics (bed linens, bathroom and kitchen items) and home furnishings (cookware and cutlery, small household appliances, picture frames, and more). 
  • Healthcare providers know the importance of preserving and protecting their data. Not only are they liable by regulations, but the loss of medical records leads to privacy violations, and worse can lead to a loss of life.