Table 4-10 Coupling link options that are supported on z15 Internal Coupling link The maximum number of combined external coupling links (active CE LR, ICA SR links) is  160 per z15 server. z15 servers support up to 384 coupling CHPIDs per CPC. A z15 coupling  link support summary is shown in Figure 4-4 on page 197. Consider the following points: For more information about distance support for coupling links, see  System z End-to-End  Extended Distance Guide , SG24-8047 . IC links are Licensed Internal Code-defined links to connect a CF to a z/OS logical partition in  the same CPC. These links are available on all IBM Z platforms. The IC link is an IBM Z  coupling connectivity option that enables high-speed, efficient communication between a CF  partition and one or more z/OS logical partitions that are running on the same CPC. The IC is  a linkless connection (implemented in LIC) and does not require any hardware or cabling. An IC link is a fast coupling link that uses memory-to-memory data transfers. IC links do not  have PCHID numbers, but do require CHPIDs. IC links have the following attributes: GLYPH<SM590000> The maximum supported links depends on the IBM Z model or capacity feature code and  the numbers are marked with an asterisk (*). GLYPH<SM590000> z15 ICA SR maximum depends on the number of CPU drawers. A total of 12 PCIe+  fanouts are used per CPU drawer, which gives a maximum of 24 ICA SR ports. The z15  machine maximum ICA SR1.1 and ICA SR ports combined is 96. GLYPH<SM590000> They provide the fastest connectivity that is significantly faster than external link  alternatives. GLYPH<SM590000> They result in better coupling efficiency than with external links, effectively reducing the  CPU cost that is associated with Parallel Sysplex. 198  IBM z15 (8561) Technical Guide Type Description Feature Code Link  rate Max  unrepeated  distance Maximum number of supported links z15 z14  ZR1 z14 z13s z13 CE LR Coupling  Express LR 0433 10 Gbps 10 kms (6.2 miles) 64 32 64 32 64 ICA SR1.1 Integrated  Coupling  Adapter 0176 8 GBps 150 meters  (492 feet) 96 N/A N/A N/A N/A ICA SR Integrated  Coupling  Adapter 0172 8 GBps 150 meters  (492 feet) 96 16 80 16 40 IC Integrated  Coupling  Adapter N/A Internal  speeds N / A 6 43 23 23 HCA3-O LR InfiniBand  Long Reach  (1 x IFB) 0170 10 kms (6.2 miles) N/A N/A 64 32 64 HCA3-O InfiniBand (12 x IFB) 0171 150 meters  (492 feet) N/A N/A 32 16 32